TY  - JOUR
AU  - Gaković, Biljana
AU  - Zamfirescu, Marian
AU  - Panjan, Peter
AU  - Luculescu, Catalin Romeo
AU  - Albu, Catalina
AU  - Petrović, Suzana
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12713
AB  - The study of ablation and the laser-induced periodic surface structure (LIPSS) creation during the static and dynamic ultrafast laser (UFL) processing of the Al2O3/TiAlN protective coating is reported. The static irradiation was done with 10 successive pulses while scanning irradiation was performed with sample scanning. The laser ablation was studied by analysis of the surface morphology and elemental composition. The selective ablations manifest as circular craters or lines/micro-channels. The borders are very sharp without debris and hydrodynamic features. LIPSSs were formed at the bottoms of craters and microchannels. The periodicity of the created LIPSSs has shown a trend of increase with the pulse energy. Depending on the applied laser fuence the elemental composition in the centre of the craters confrmed the complete removal of the Al2O3 layer and partial ablation of the second TiAlN. The Al2O3 layer and part of TiAlN were ablated in micro-channels too.
T2  - Optical and Quantum Electronics
T1  - Laser ablation and LIPSS formation at static and dynamic multi-pulse regime on protective Al2O3/TiAlN coating
VL  - 56
IS  - 4
DO  - 10.1007/s11082-023-06238-x
ER  - 

@article{
author = "Gaković, Biljana and Zamfirescu, Marian and Panjan, Peter and Luculescu, Catalin Romeo and Albu, Catalina and Petrović, Suzana",
year = "2024",
abstract = "The study of ablation and the laser-induced periodic surface structure (LIPSS) creation during the static and dynamic ultrafast laser (UFL) processing of the Al2O3/TiAlN protective coating is reported. The static irradiation was done with 10 successive pulses while scanning irradiation was performed with sample scanning. The laser ablation was studied by analysis of the surface morphology and elemental composition. The selective ablations manifest as circular craters or lines/micro-channels. The borders are very sharp without debris and hydrodynamic features. LIPSSs were formed at the bottoms of craters and microchannels. The periodicity of the created LIPSSs has shown a trend of increase with the pulse energy. Depending on the applied laser fuence the elemental composition in the centre of the craters confrmed the complete removal of the Al2O3 layer and partial ablation of the second TiAlN. The Al2O3 layer and part of TiAlN were ablated in micro-channels too.",
journal = "Optical and Quantum Electronics",
title = "Laser ablation and LIPSS formation at static and dynamic multi-pulse regime on protective Al2O3/TiAlN coating",
volume = "56",
number = "4",
doi = "10.1007/s11082-023-06238-x"
}

Gaković, B., Zamfirescu, M., Panjan, P., Luculescu, C. R., Albu, C.,& Petrović, S.. (2024). Laser ablation and LIPSS formation at static and dynamic multi-pulse regime on protective Al2O3/TiAlN coating. in Optical and Quantum Electronics, 56(4).
https://doi.org/10.1007/s11082-023-06238-x

Gaković B, Zamfirescu M, Panjan P, Luculescu CR, Albu C, Petrović S. Laser ablation and LIPSS formation at static and dynamic multi-pulse regime on protective Al2O3/TiAlN coating. in Optical and Quantum Electronics. 2024;56(4).
doi:10.1007/s11082-023-06238-x .

Gaković, Biljana, Zamfirescu, Marian, Panjan, Peter, Luculescu, Catalin Romeo, Albu, Catalina, Petrović, Suzana, "Laser ablation and LIPSS formation at static and dynamic multi-pulse regime on protective Al2O3/TiAlN coating" in Optical and Quantum Electronics, 56, no. 4 (2024),
https://doi.org/10.1007/s11082-023-06238-x . .

TY  - JOUR
AU  - Tadić, Marin
AU  - Panjan, Matjaž
AU  - Čekada, Miha
AU  - Jagličić, Zvonko
AU  - Pregelj, Matej
AU  - Spreitzer, Matjaž
AU  - Panjan, Peter
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12839
AB  - In the literature, a magnetic “easy” axis perpendicular to the film plane at room temperature (i.e., perpendicular magnetic anisotropy - PMA) has been reported in Ni (nickel) layers with thicknesses below ≈15 nm. In this work, we observed room-temperature PMA in a-Si/Ni/a-Si (where a-Si denotes amorphous silicon) thin film structures with nickel layer thicker than 15 nm. Two layered structures were prepared by DC/RF triode sputtering: [a-Si/Ni/a-Si] sandwich structure and [a-Si/Ni/a-Si]5 multilayer structure. The cross sectional STEM revealed uniform Ni layers with thicknesses of ≈17 nm in [a-Si/Ni/a-Si]5 – multilayer and ≈28 nm in [a-Si/Ni/a-Si] – single-layer whereas amorphous Si layers were ≈15 nm and 170 nm thick, respectively. An amorphous Ni–Si interphase was also observed in the layered structures. The XRD showed patterns for fcc-Ni with dominant (111) orientation. No other crystalline phases were observed in the XRD patterns. To our knowledge, there are no literature reports of easy magnetization direction perpendicular to the film plane at room temperature for Ni layers with thickness of ≈28 nm as presented in this work. The origin of PMA in a-Si/Ni/a-Si films may be mainly attributed to the magnetoelastic anisotropy whereas the secondary source of PMA is believed to be the surface anisotropy and magnetocrystalline anisotropy of [111] columnar grains. Amorphous silicon layers (substrate) do not have a well-defined lattice structure like crystalline substrates. Therefore, they do not induce strains in the nickel layers through lattice mismatch as in the case of epitaxy. The strains can be caused by other factors such as diffusion-induced strain, thermal expansion mismatch or intrinsic stresses during the growth process. These results could be important for applications in memory devices, sensors, logic chips, magneto-optic, magneto-electronic and spintronic devices and in fundamental research, as well as first step toward preparation and understanding of the PMA in thick nickel layers.
T2  - Ceramics International
T1  - Perpendicular magnetic anisotropy at room-temperature in sputtered a-Si/Ni/a-Si layered structure with thick Ni (nickel) layers
VL  - 49
IS  - 19
SP  - 32068
EP  - 32077
DO  - 10.1016/j.ceramint.2023.07.174
ER  - 

@article{
author = "Tadić, Marin and Panjan, Matjaž and Čekada, Miha and Jagličić, Zvonko and Pregelj, Matej and Spreitzer, Matjaž and Panjan, Peter",
year = "2023",
abstract = "In the literature, a magnetic “easy” axis perpendicular to the film plane at room temperature (i.e., perpendicular magnetic anisotropy - PMA) has been reported in Ni (nickel) layers with thicknesses below ≈15 nm. In this work, we observed room-temperature PMA in a-Si/Ni/a-Si (where a-Si denotes amorphous silicon) thin film structures with nickel layer thicker than 15 nm. Two layered structures were prepared by DC/RF triode sputtering: [a-Si/Ni/a-Si] sandwich structure and [a-Si/Ni/a-Si]5 multilayer structure. The cross sectional STEM revealed uniform Ni layers with thicknesses of ≈17 nm in [a-Si/Ni/a-Si]5 – multilayer and ≈28 nm in [a-Si/Ni/a-Si] – single-layer whereas amorphous Si layers were ≈15 nm and 170 nm thick, respectively. An amorphous Ni–Si interphase was also observed in the layered structures. The XRD showed patterns for fcc-Ni with dominant (111) orientation. No other crystalline phases were observed in the XRD patterns. To our knowledge, there are no literature reports of easy magnetization direction perpendicular to the film plane at room temperature for Ni layers with thickness of ≈28 nm as presented in this work. The origin of PMA in a-Si/Ni/a-Si films may be mainly attributed to the magnetoelastic anisotropy whereas the secondary source of PMA is believed to be the surface anisotropy and magnetocrystalline anisotropy of [111] columnar grains. Amorphous silicon layers (substrate) do not have a well-defined lattice structure like crystalline substrates. Therefore, they do not induce strains in the nickel layers through lattice mismatch as in the case of epitaxy. The strains can be caused by other factors such as diffusion-induced strain, thermal expansion mismatch or intrinsic stresses during the growth process. These results could be important for applications in memory devices, sensors, logic chips, magneto-optic, magneto-electronic and spintronic devices and in fundamental research, as well as first step toward preparation and understanding of the PMA in thick nickel layers.",
journal = "Ceramics International",
title = "Perpendicular magnetic anisotropy at room-temperature in sputtered a-Si/Ni/a-Si layered structure with thick Ni (nickel) layers",
volume = "49",
number = "19",
pages = "32068-32077",
doi = "10.1016/j.ceramint.2023.07.174"
}

Tadić, M., Panjan, M., Čekada, M., Jagličić, Z., Pregelj, M., Spreitzer, M.,& Panjan, P.. (2023). Perpendicular magnetic anisotropy at room-temperature in sputtered a-Si/Ni/a-Si layered structure with thick Ni (nickel) layers. in Ceramics International, 49(19), 32068-32077.
https://doi.org/10.1016/j.ceramint.2023.07.174

Tadić M, Panjan M, Čekada M, Jagličić Z, Pregelj M, Spreitzer M, Panjan P. Perpendicular magnetic anisotropy at room-temperature in sputtered a-Si/Ni/a-Si layered structure with thick Ni (nickel) layers. in Ceramics International. 2023;49(19):32068-32077.
doi:10.1016/j.ceramint.2023.07.174 .

Tadić, Marin, Panjan, Matjaž, Čekada, Miha, Jagličić, Zvonko, Pregelj, Matej, Spreitzer, Matjaž, Panjan, Peter, "Perpendicular magnetic anisotropy at room-temperature in sputtered a-Si/Ni/a-Si layered structure with thick Ni (nickel) layers" in Ceramics International, 49, no. 19 (2023):32068-32077,
https://doi.org/10.1016/j.ceramint.2023.07.174 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Kudryashov, S. I.
AU  - Danilov, P. A.
AU  - Milovanović, D.
AU  - Panjan, Peter
AU  - Bezhanov, S. G.
AU  - Uryupin, S. A.
AU  - Ionin, A. A.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10012
AB  - Results concerning the controllable ablation of nano-layered thin films (NLTF) by femtosecond laser pulses are presented. Investigated samples were titanium-aluminum bilayers, deposited on a silicon substrate, with the top titanium or aluminum layer of variable thickness on the surface. Irradiation was done in ambient air with single femtosecond laser pulses under standard laboratory conditions. The samples were analyzed by complementary methods of optical and scanning electron microscopy and optical profilometry, exhibiting laser-fluence-dependent ablative removal either of the top layer or the entire bilayer or even partial ablation of the underlying silicon substrate. The removal (spallation) threshold fluences for the topmost layer are scalable versus its thickness almost irrespectively of its material, being rather selective for the Ti-coated samples and much less selective for the Al-coated samples. The removal of the entire bilayers was found to be strongly influenced by electronic properties of the underlying metallic layer, dictating the NLTF-Si adhesion, heat conduction, and capacity in the NLTFs toward the NLTF-Si interface and beyond, as well as by their thermophysical characteristics, e.g., almost twice higher melting temperature and enthalpy for Ti. As a result, precise fs-laser machining of the entire NLTFs is pronounced and selective for the samples with the fusible Al at the low-adhesion Al-Si interfaces, compared with the incomplete NLTF removal from the high-adhesion and refractory Ti-Si interfaces.
T2  - Applied Optics
T1  - Controllable ablative machining of Al/Ti and Ti/Al nano-layers on a Si substrate by single-pulse femtosecond laser irradiation
VL  - 60
IS  - 31
SP  - H12
EP  - H19
DO  - 10.1364/AO.432691
ER  - 

@article{
author = "Gaković, Biljana M. and Kudryashov, S. I. and Danilov, P. A. and Milovanović, D. and Panjan, Peter and Bezhanov, S. G. and Uryupin, S. A. and Ionin, A. A.",
year = "2021",
abstract = "Results concerning the controllable ablation of nano-layered thin films (NLTF) by femtosecond laser pulses are presented. Investigated samples were titanium-aluminum bilayers, deposited on a silicon substrate, with the top titanium or aluminum layer of variable thickness on the surface. Irradiation was done in ambient air with single femtosecond laser pulses under standard laboratory conditions. The samples were analyzed by complementary methods of optical and scanning electron microscopy and optical profilometry, exhibiting laser-fluence-dependent ablative removal either of the top layer or the entire bilayer or even partial ablation of the underlying silicon substrate. The removal (spallation) threshold fluences for the topmost layer are scalable versus its thickness almost irrespectively of its material, being rather selective for the Ti-coated samples and much less selective for the Al-coated samples. The removal of the entire bilayers was found to be strongly influenced by electronic properties of the underlying metallic layer, dictating the NLTF-Si adhesion, heat conduction, and capacity in the NLTFs toward the NLTF-Si interface and beyond, as well as by their thermophysical characteristics, e.g., almost twice higher melting temperature and enthalpy for Ti. As a result, precise fs-laser machining of the entire NLTFs is pronounced and selective for the samples with the fusible Al at the low-adhesion Al-Si interfaces, compared with the incomplete NLTF removal from the high-adhesion and refractory Ti-Si interfaces.",
journal = "Applied Optics",
title = "Controllable ablative machining of Al/Ti and Ti/Al nano-layers on a Si substrate by single-pulse femtosecond laser irradiation",
volume = "60",
number = "31",
pages = "H12-H19",
doi = "10.1364/AO.432691"
}

Gaković, B. M., Kudryashov, S. I., Danilov, P. A., Milovanović, D., Panjan, P., Bezhanov, S. G., Uryupin, S. A.,& Ionin, A. A.. (2021). Controllable ablative machining of Al/Ti and Ti/Al nano-layers on a Si substrate by single-pulse femtosecond laser irradiation. in Applied Optics, 60(31), H12-H19.
https://doi.org/10.1364/AO.432691

Gaković BM, Kudryashov SI, Danilov PA, Milovanović D, Panjan P, Bezhanov SG, Uryupin SA, Ionin AA. Controllable ablative machining of Al/Ti and Ti/Al nano-layers on a Si substrate by single-pulse femtosecond laser irradiation. in Applied Optics. 2021;60(31):H12-H19.
doi:10.1364/AO.432691 .

Gaković, Biljana M., Kudryashov, S. I., Danilov, P. A., Milovanović, D., Panjan, Peter, Bezhanov, S. G., Uryupin, S. A., Ionin, A. A., "Controllable ablative machining of Al/Ti and Ti/Al nano-layers on a Si substrate by single-pulse femtosecond laser irradiation" in Applied Optics, 60, no. 31 (2021):H12-H19,
https://doi.org/10.1364/AO.432691 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Danilov, Pavel A.
AU  - Kudryashov, Sergey I.
AU  - Milovanović, Dubravka S.
AU  - Radulović, Aleksandra 
AU  - Panjan, Peter
AU  - Ionin, Andrey A.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10038
AB  - Results regarding morphological and compositional changes of bimetallic thin film (BMTF), composed of aluminium (Al) and titanium (Ti) nano-layers, by single fs laser pulses, are presented. Laser irradiation was conducted in the air with focused, linearly polarized laser pulses, the duration being 300 fs, wavelength 515 nm, and pulse energy up to 1.2μJ. Effects of the variations of the pulse energy on the changes were studied. In the experiment, single pulse energy values from 0.03 to 0.08 μ J caused ablation–photomechanical spallation of the upper part of BMTF layer from the Si substrate, without ablation of the whole film. Irradiation at higher pulse energies gradually removed the whole BMTF and even a part of the Si substrate. We explained the influence of different electron–phonon dynamics, in the case of multilayered thin films composed of Al and Ti, on BMTF ablation. Damage/ablation threshold, which is minimal pulse energy/fluence sufficient for starting ablation, was calculated. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.
T2  - European Physical Journal D. Atoms, Molecules, Clusters and Optical Physics
T1  - The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses
VL  - 75
IS  - 11
DO  - 10.1140/epjd/s10053-021-00292-4
ER  - 

@article{
author = "Gaković, Biljana M. and Danilov, Pavel A. and Kudryashov, Sergey I. and Milovanović, Dubravka S. and Radulović, Aleksandra  and Panjan, Peter and Ionin, Andrey A.",
year = "2021",
abstract = "Results regarding morphological and compositional changes of bimetallic thin film (BMTF), composed of aluminium (Al) and titanium (Ti) nano-layers, by single fs laser pulses, are presented. Laser irradiation was conducted in the air with focused, linearly polarized laser pulses, the duration being 300 fs, wavelength 515 nm, and pulse energy up to 1.2μJ. Effects of the variations of the pulse energy on the changes were studied. In the experiment, single pulse energy values from 0.03 to 0.08 μ J caused ablation–photomechanical spallation of the upper part of BMTF layer from the Si substrate, without ablation of the whole film. Irradiation at higher pulse energies gradually removed the whole BMTF and even a part of the Si substrate. We explained the influence of different electron–phonon dynamics, in the case of multilayered thin films composed of Al and Ti, on BMTF ablation. Damage/ablation threshold, which is minimal pulse energy/fluence sufficient for starting ablation, was calculated. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.",
journal = "European Physical Journal D. Atoms, Molecules, Clusters and Optical Physics",
title = "The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses",
volume = "75",
number = "11",
doi = "10.1140/epjd/s10053-021-00292-4"
}

Gaković, B. M., Danilov, P. A., Kudryashov, S. I., Milovanović, D. S., Radulović, A., Panjan, P.,& Ionin, A. A.. (2021). The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses. in European Physical Journal D. Atoms, Molecules, Clusters and Optical Physics, 75(11).
https://doi.org/10.1140/epjd/s10053-021-00292-4

Gaković BM, Danilov PA, Kudryashov SI, Milovanović DS, Radulović A, Panjan P, Ionin AA. The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses. in European Physical Journal D. Atoms, Molecules, Clusters and Optical Physics. 2021;75(11).
doi:10.1140/epjd/s10053-021-00292-4 .

Gaković, Biljana M., Danilov, Pavel A., Kudryashov, Sergey I., Milovanović, Dubravka S., Radulović, Aleksandra , Panjan, Peter, Ionin, Andrey A., "The morphological and compositional changes of bimetallic Ti/Al thin film induced by ultra-short laser pulses" in European Physical Journal D. Atoms, Molecules, Clusters and Optical Physics, 75, no. 11 (2021),
https://doi.org/10.1140/epjd/s10053-021-00292-4 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Panjan, Peter
AU  - Kovač, Janez
AU  - Lazović, Vladimir M.
AU  - Ristoscu, Carmen
AU  - Negut, Irina
AU  - Mihailescu, Ion N.
PY  - 2018
UR  - http://link.springer.com/10.1007/s11082-018-1475-3
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7686
AB  - The oxidation behaviour and morphological modification of CrN/(Cr,V)N coatings on Si wafers were studied after UV nanosecond laser (wavelength 248 nm, pulse duration 25 ns) processing in ambient air. The evolution of the surface composition and microstructure with the number of accumulated/subsequent pulses was systematically analysed depending on the initial content of vanadium in the as-deposited coatings. Irradiation of CrN/(Cr,V)N coatings with different content of vanadium was carried out at a fluence of 0.17 J cm−2with different number of pulses. The concentration of metallic components was fairly homogeneous distributed throughout the sample. However, on surface and in sub-surface regions the contents of Cr and V are diminished due to laser-induced oxidation. The composition and thickness of forming oxides mixture, Cr2O3and V2O5, are depending on the number of applied laser pulses and the initial vanadium content. The asymmetric progress of surface morphology is characterized by the formation of grainy structures at peripheries and the appearance of cracks and irregular closed shapes in the centre of the irradiation area.
T2  - Optical and Quantum Electronics
T1  - Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses
VL  - 50
IS  - 5
SP  - 208
DO  - 10.1007/s11082-018-1475-3
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Panjan, Peter and Kovač, Janez and Lazović, Vladimir M. and Ristoscu, Carmen and Negut, Irina and Mihailescu, Ion N.",
year = "2018",
abstract = "The oxidation behaviour and morphological modification of CrN/(Cr,V)N coatings on Si wafers were studied after UV nanosecond laser (wavelength 248 nm, pulse duration 25 ns) processing in ambient air. The evolution of the surface composition and microstructure with the number of accumulated/subsequent pulses was systematically analysed depending on the initial content of vanadium in the as-deposited coatings. Irradiation of CrN/(Cr,V)N coatings with different content of vanadium was carried out at a fluence of 0.17 J cm−2with different number of pulses. The concentration of metallic components was fairly homogeneous distributed throughout the sample. However, on surface and in sub-surface regions the contents of Cr and V are diminished due to laser-induced oxidation. The composition and thickness of forming oxides mixture, Cr2O3and V2O5, are depending on the number of applied laser pulses and the initial vanadium content. The asymmetric progress of surface morphology is characterized by the formation of grainy structures at peripheries and the appearance of cracks and irregular closed shapes in the centre of the irradiation area.",
journal = "Optical and Quantum Electronics",
title = "Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses",
volume = "50",
number = "5",
pages = "208",
doi = "10.1007/s11082-018-1475-3"
}

Petrović, S., Gaković, B. M., Panjan, P., Kovač, J., Lazović, V. M., Ristoscu, C., Negut, I.,& Mihailescu, I. N.. (2018). Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses. in Optical and Quantum Electronics, 50(5), 208.
https://doi.org/10.1007/s11082-018-1475-3

Petrović S, Gaković BM, Panjan P, Kovač J, Lazović VM, Ristoscu C, Negut I, Mihailescu IN. Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses. in Optical and Quantum Electronics. 2018;50(5):208.
doi:10.1007/s11082-018-1475-3 .

Petrović, Suzana, Gaković, Biljana M., Panjan, Peter, Kovač, Janez, Lazović, Vladimir M., Ristoscu, Carmen, Negut, Irina, Mihailescu, Ion N., "Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses" in Optical and Quantum Electronics, 50, no. 5 (2018):208,
https://doi.org/10.1007/s11082-018-1475-3 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Petrović, Suzana
AU  - Albu, C.
AU  - Zamfirescu, M.
AU  - Panjan, Peter
AU  - Milovanović, Dubravka S.
AU  - Popescu-Pelin, G.
AU  - Mihailescu, Ion N.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1326
AB  - Processing of AlTiN/TiN multilayered hard coatings by femtosecond (fs) laser pulses has been investigated. Irradiation was performed in air with linearly polarized laser radiation with pulses of 200 fs duration at 775 nm wavelength. Single or 1000 subsequent laser pulses were directed at normal incidence towards target surface. Laser energy per pulse was adjusted from 0.5 to 50 mu J and corresponding fluence was 0.17-17.5 J cm(-2). The as deposited and laser-ablated samples were characterized by optical confocal microscopy, optical profilometry and scanning and transmition electron microscopy. In case of the AlTiN/TiN coating, a single-pulse damage threshold of 0.41 J cm(-2) was estimated. Well defined holes/craters with diameters from 7 to 35 mu m, up to 40 mu m depth were drilled, depending on laser pulse energy and number, after 1000 laser pulses. For small energy/fluence, laser induced periodical surface structures were observed. A model is discussed which can account for these features by the accumulation effect during multi-pulse irradiation. The forming craters can prove useful for fabrication of micron solid state lubricant reservoirs in the protective coating-steel system.
T2  - Optics and Laser Technology
T1  - Precise femtosecond laser crater fabrication in hard nanolayered AlTiN/TiN coating on steel substrate
VL  - 89
SP  - 200
EP  - 207
DO  - 10.1016/j.optlastec.2016.10.015
ER  - 

@article{
author = "Gaković, Biljana M. and Petrović, Suzana and Albu, C. and Zamfirescu, M. and Panjan, Peter and Milovanović, Dubravka S. and Popescu-Pelin, G. and Mihailescu, Ion N.",
year = "2017",
abstract = "Processing of AlTiN/TiN multilayered hard coatings by femtosecond (fs) laser pulses has been investigated. Irradiation was performed in air with linearly polarized laser radiation with pulses of 200 fs duration at 775 nm wavelength. Single or 1000 subsequent laser pulses were directed at normal incidence towards target surface. Laser energy per pulse was adjusted from 0.5 to 50 mu J and corresponding fluence was 0.17-17.5 J cm(-2). The as deposited and laser-ablated samples were characterized by optical confocal microscopy, optical profilometry and scanning and transmition electron microscopy. In case of the AlTiN/TiN coating, a single-pulse damage threshold of 0.41 J cm(-2) was estimated. Well defined holes/craters with diameters from 7 to 35 mu m, up to 40 mu m depth were drilled, depending on laser pulse energy and number, after 1000 laser pulses. For small energy/fluence, laser induced periodical surface structures were observed. A model is discussed which can account for these features by the accumulation effect during multi-pulse irradiation. The forming craters can prove useful for fabrication of micron solid state lubricant reservoirs in the protective coating-steel system.",
journal = "Optics and Laser Technology",
title = "Precise femtosecond laser crater fabrication in hard nanolayered AlTiN/TiN coating on steel substrate",
volume = "89",
pages = "200-207",
doi = "10.1016/j.optlastec.2016.10.015"
}

Gaković, B. M., Petrović, S., Albu, C., Zamfirescu, M., Panjan, P., Milovanović, D. S., Popescu-Pelin, G.,& Mihailescu, I. N.. (2017). Precise femtosecond laser crater fabrication in hard nanolayered AlTiN/TiN coating on steel substrate. in Optics and Laser Technology, 89, 200-207.
https://doi.org/10.1016/j.optlastec.2016.10.015

Gaković BM, Petrović S, Albu C, Zamfirescu M, Panjan P, Milovanović DS, Popescu-Pelin G, Mihailescu IN. Precise femtosecond laser crater fabrication in hard nanolayered AlTiN/TiN coating on steel substrate. in Optics and Laser Technology. 2017;89:200-207.
doi:10.1016/j.optlastec.2016.10.015 .

Gaković, Biljana M., Petrović, Suzana, Albu, C., Zamfirescu, M., Panjan, Peter, Milovanović, Dubravka S., Popescu-Pelin, G., Mihailescu, Ion N., "Precise femtosecond laser crater fabrication in hard nanolayered AlTiN/TiN coating on steel substrate" in Optics and Laser Technology, 89 (2017):200-207,
https://doi.org/10.1016/j.optlastec.2016.10.015 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Kovač, Janez
AU  - Panjan, Peter
AU  - Mitrić, Miodrag
AU  - Pjević, Dejan J.
AU  - Kovačević, Aleksander
AU  - Jelenković, Branislav
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1746
AB  - Formation of periodic nanostructures on the Ti/5x(Al/Ti)/Si multilayers induced by picosecond laser pulses is studied in order to better understand the formation of a laser-induced periodic surface structure (LIPSS). At fluence slightly below the ablation threshold, the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization is observed on the irradiated area. Prolonged irradiation while scanning results in the formation of a high spatial frequency-LIPSS (HSFL), on top of the LSFLs, creating a co-existence parallel periodic structure. HSFL was oriented parallel to the incident laser polarization. Intermixing between the Al and Ti layers with the formation of Al-Ti intermetallic compounds was achieved during the irradiation. The intermetallic region was formed mostly within the heat affected zone of the sample. Surface segregation of aluminium with partial ablation of the top layer of titanium was followed by the formation of an ultra-thin Al2O3 film on the surface of the multi-layered structure. Published by AIP Publishing.
T2  - Journal of Applied Physics
T1  - Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers
VL  - 122
IS  - 11
DO  - 10.1063/1.4985830
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Kovač, Janez and Panjan, Peter and Mitrić, Miodrag and Pjević, Dejan J. and Kovačević, Aleksander and Jelenković, Branislav",
year = "2017",
abstract = "Formation of periodic nanostructures on the Ti/5x(Al/Ti)/Si multilayers induced by picosecond laser pulses is studied in order to better understand the formation of a laser-induced periodic surface structure (LIPSS). At fluence slightly below the ablation threshold, the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization is observed on the irradiated area. Prolonged irradiation while scanning results in the formation of a high spatial frequency-LIPSS (HSFL), on top of the LSFLs, creating a co-existence parallel periodic structure. HSFL was oriented parallel to the incident laser polarization. Intermixing between the Al and Ti layers with the formation of Al-Ti intermetallic compounds was achieved during the irradiation. The intermetallic region was formed mostly within the heat affected zone of the sample. Surface segregation of aluminium with partial ablation of the top layer of titanium was followed by the formation of an ultra-thin Al2O3 film on the surface of the multi-layered structure. Published by AIP Publishing.",
journal = "Journal of Applied Physics",
title = "Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers",
volume = "122",
number = "11",
doi = "10.1063/1.4985830"
}

Petrović, S., Peruško, D., Kovač, J., Panjan, P., Mitrić, M., Pjević, D. J., Kovačević, A.,& Jelenković, B.. (2017). Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers. in Journal of Applied Physics, 122(11).
https://doi.org/10.1063/1.4985830

Petrović S, Peruško D, Kovač J, Panjan P, Mitrić M, Pjević DJ, Kovačević A, Jelenković B. Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers. in Journal of Applied Physics. 2017;122(11).
doi:10.1063/1.4985830 .

Petrović, Suzana, Peruško, Davor, Kovač, Janez, Panjan, Peter, Mitrić, Miodrag, Pjević, Dejan J., Kovačević, Aleksander, Jelenković, Branislav, "Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers" in Journal of Applied Physics, 122, no. 11 (2017),
https://doi.org/10.1063/1.4985830 . .

TY  - JOUR
AU  - Salatić, Branislav
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Čekada, Miha
AU  - Panjan, Peter
AU  - Pantelić, Dejan
AU  - Jelenković, Branislav
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/858
AB  - The surface morphology of the ablation craters created in the multilayer 10x(Al/Ti)/Si system by nanosecond laser pulses at single- and dual wavelength has been studied experimentally and numerically. A complex multilayer thin film including ten (Al/Ti) bilayers deposited by ion sputtering on Si(1 0 0) substrate to a total thickness of 260 nm were illuminated at different laser irradiance in the range 0.25-3.5 x 10(9)W cm(-2). Single pulse laser irradiation was done at normal incidence in air, with the single wavelength, either at 532 nm or 1064 nm or with both laser light simultaneously in the ratio of 1: 10 for energy per pulse between second harmonic and 1064 nm. Most of the absorbed laser energy was rapidly transformed into heat, producing intensive modifications of composition and morphology on the sample surface. The results show an increase in surface roughness, formation of specific nanostructures, appearance of hydrodynamic features and ablation of surface material with crater formation. Applying a small fraction (10%) of the second harmonic in dual-wavelength pulses, a modification of the 10x(Al/Ti)/Si system by a single laser pulse was reflected in the formation of wider and/or deeper craters. Numerical calculations show that the main physical mechanism in ablation process is normal evaporation without phase explosion. The calculated and experimental results agree relatively well for the whole irradiance range, what makes the model applicable to complex Al/Ti multilayer systems. (C) 2015 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Applied Surface Science
T1  - Single- and dual-wavelength laser pulses induced modification in 10x(Al/Ti)/Si multilayer system
VL  - 360
SP  - 559
EP  - 565
DO  - 10.1016/j.apsusc.2015.10.203
ER  - 

@article{
author = "Salatić, Branislav and Petrović, Suzana and Peruško, Davor and Čekada, Miha and Panjan, Peter and Pantelić, Dejan and Jelenković, Branislav",
year = "2016",
abstract = "The surface morphology of the ablation craters created in the multilayer 10x(Al/Ti)/Si system by nanosecond laser pulses at single- and dual wavelength has been studied experimentally and numerically. A complex multilayer thin film including ten (Al/Ti) bilayers deposited by ion sputtering on Si(1 0 0) substrate to a total thickness of 260 nm were illuminated at different laser irradiance in the range 0.25-3.5 x 10(9)W cm(-2). Single pulse laser irradiation was done at normal incidence in air, with the single wavelength, either at 532 nm or 1064 nm or with both laser light simultaneously in the ratio of 1: 10 for energy per pulse between second harmonic and 1064 nm. Most of the absorbed laser energy was rapidly transformed into heat, producing intensive modifications of composition and morphology on the sample surface. The results show an increase in surface roughness, formation of specific nanostructures, appearance of hydrodynamic features and ablation of surface material with crater formation. Applying a small fraction (10%) of the second harmonic in dual-wavelength pulses, a modification of the 10x(Al/Ti)/Si system by a single laser pulse was reflected in the formation of wider and/or deeper craters. Numerical calculations show that the main physical mechanism in ablation process is normal evaporation without phase explosion. The calculated and experimental results agree relatively well for the whole irradiance range, what makes the model applicable to complex Al/Ti multilayer systems. (C) 2015 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Applied Surface Science",
title = "Single- and dual-wavelength laser pulses induced modification in 10x(Al/Ti)/Si multilayer system",
volume = "360",
pages = "559-565",
doi = "10.1016/j.apsusc.2015.10.203"
}

Salatić, B., Petrović, S., Peruško, D., Čekada, M., Panjan, P., Pantelić, D.,& Jelenković, B.. (2016). Single- and dual-wavelength laser pulses induced modification in 10x(Al/Ti)/Si multilayer system. in Applied Surface Science
Elsevier., 360, 559-565.
https://doi.org/10.1016/j.apsusc.2015.10.203

Salatić B, Petrović S, Peruško D, Čekada M, Panjan P, Pantelić D, Jelenković B. Single- and dual-wavelength laser pulses induced modification in 10x(Al/Ti)/Si multilayer system. in Applied Surface Science. 2016;360:559-565.
doi:10.1016/j.apsusc.2015.10.203 .

Salatić, Branislav, Petrović, Suzana, Peruško, Davor, Čekada, Miha, Panjan, Peter, Pantelić, Dejan, Jelenković, Branislav, "Single- and dual-wavelength laser pulses induced modification in 10x(Al/Ti)/Si multilayer system" in Applied Surface Science, 360 (2016):559-565,
https://doi.org/10.1016/j.apsusc.2015.10.203 . .

TY  - JOUR
AU  - Trtica, Milan
AU  - Limpouch, Jiri
AU  - Gavrilov, Peter T.
AU  - Gemini, L.
AU  - Panjan, Peter
AU  - Stašić, Jelena
AU  - Milovanović, Dubravka S.
AU  - Branković, Goran O.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/715
AB  - A double layer a-CN/TiAlN coating deposited on ASP30 steel substrate was irradiated by femtosecond laser and surface modification effects were observed. Moderate laser intensities used were in the range of 10(14)-10(13) W/cm(2), while the total thickness of double layer coating was 4.8 mu m (a-CN = 0.6 and TiAlN = 4.2 mu m). Laser-induced changes of the surface showed dependence on laser intensity and number of accumulated pulses. Irradiations at the highest intensity resulted in preservation of one or both layers up to 10 pulses, while at lower intensity (10(13) W/cm(2)) a-CN layer is removed after several pulses and TiAlN is preserved up to 50 pulses. Evaluated damage threshold of the target was 0.49 J/cm(2). Lower laser intensity irradiation produced periodic surface structures (LIPSS) over the entire irradiated spot with periodicity of similar to 700 nm, almost in agreement with the laser wavelength used. Irradiations carried out at the highest laser intensity (10(14) W/cm(2)) and laser pulse count of 50 resulted in the creation of crater like damages with depth up to 20 mu m. Craters were conically shaped, implying intensive processes which took place at the surface. Generation of LIPSS as well as craters can be of great interest for contemporary technologies.
T2  - Laser and Particle Beams
T1  - Surface modification of a-CN/TiAlN double layer coating on ASP 30 steel induced by femtosecond laser with 10(13)-10(14) W/cm(2) intensity in vacuum
VL  - 33
IS  - 3
SP  - 551
EP  - 559
DO  - 10.1017/S0263034615000610
ER  - 

@article{
author = "Trtica, Milan and Limpouch, Jiri and Gavrilov, Peter T. and Gemini, L. and Panjan, Peter and Stašić, Jelena and Milovanović, Dubravka S. and Branković, Goran O.",
year = "2015",
abstract = "A double layer a-CN/TiAlN coating deposited on ASP30 steel substrate was irradiated by femtosecond laser and surface modification effects were observed. Moderate laser intensities used were in the range of 10(14)-10(13) W/cm(2), while the total thickness of double layer coating was 4.8 mu m (a-CN = 0.6 and TiAlN = 4.2 mu m). Laser-induced changes of the surface showed dependence on laser intensity and number of accumulated pulses. Irradiations at the highest intensity resulted in preservation of one or both layers up to 10 pulses, while at lower intensity (10(13) W/cm(2)) a-CN layer is removed after several pulses and TiAlN is preserved up to 50 pulses. Evaluated damage threshold of the target was 0.49 J/cm(2). Lower laser intensity irradiation produced periodic surface structures (LIPSS) over the entire irradiated spot with periodicity of similar to 700 nm, almost in agreement with the laser wavelength used. Irradiations carried out at the highest laser intensity (10(14) W/cm(2)) and laser pulse count of 50 resulted in the creation of crater like damages with depth up to 20 mu m. Craters were conically shaped, implying intensive processes which took place at the surface. Generation of LIPSS as well as craters can be of great interest for contemporary technologies.",
journal = "Laser and Particle Beams",
title = "Surface modification of a-CN/TiAlN double layer coating on ASP 30 steel induced by femtosecond laser with 10(13)-10(14) W/cm(2) intensity in vacuum",
volume = "33",
number = "3",
pages = "551-559",
doi = "10.1017/S0263034615000610"
}

Trtica, M., Limpouch, J., Gavrilov, P. T., Gemini, L., Panjan, P., Stašić, J., Milovanović, D. S.,& Branković, G. O.. (2015). Surface modification of a-CN/TiAlN double layer coating on ASP 30 steel induced by femtosecond laser with 10(13)-10(14) W/cm(2) intensity in vacuum. in Laser and Particle Beams, 33(3), 551-559.
https://doi.org/10.1017/S0263034615000610

Trtica M, Limpouch J, Gavrilov PT, Gemini L, Panjan P, Stašić J, Milovanović DS, Branković GO. Surface modification of a-CN/TiAlN double layer coating on ASP 30 steel induced by femtosecond laser with 10(13)-10(14) W/cm(2) intensity in vacuum. in Laser and Particle Beams. 2015;33(3):551-559.
doi:10.1017/S0263034615000610 .

Trtica, Milan, Limpouch, Jiri, Gavrilov, Peter T., Gemini, L., Panjan, Peter, Stašić, Jelena, Milovanović, Dubravka S., Branković, Goran O., "Surface modification of a-CN/TiAlN double layer coating on ASP 30 steel induced by femtosecond laser with 10(13)-10(14) W/cm(2) intensity in vacuum" in Laser and Particle Beams, 33, no. 3 (2015):551-559,
https://doi.org/10.1017/S0263034615000610 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Kovač, Janez
AU  - Panjan, Peter
AU  - Stratakis, Emmanuel
AU  - Trtica, Milan
AU  - Fotakis, C.
AU  - Jelenković, Branislav
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/103
AB  - The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm(-2), when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultra-thin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al2O3 and Fe2O3, depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al2O3 and Fe2O3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.
T2  - Journal of Materials Science
T1  - Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure
VL  - 49
IS  - 22
SP  - 7900
EP  - 7907
DO  - 10.1007/s10853-014-8502-y
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Kovač, Janez and Panjan, Peter and Stratakis, Emmanuel and Trtica, Milan and Fotakis, C. and Jelenković, Branislav",
year = "2014",
abstract = "The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm(-2), when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultra-thin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al2O3 and Fe2O3, depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al2O3 and Fe2O3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.",
journal = "Journal of Materials Science",
title = "Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure",
volume = "49",
number = "22",
pages = "7900-7907",
doi = "10.1007/s10853-014-8502-y"
}

Petrović, S., Gaković, B. M., Kovač, J., Panjan, P., Stratakis, E., Trtica, M., Fotakis, C.,& Jelenković, B.. (2014). Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure. in Journal of Materials Science, 49(22), 7900-7907.
https://doi.org/10.1007/s10853-014-8502-y

Petrović S, Gaković BM, Kovač J, Panjan P, Stratakis E, Trtica M, Fotakis C, Jelenković B. Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure. in Journal of Materials Science. 2014;49(22):7900-7907.
doi:10.1007/s10853-014-8502-y .

Petrović, Suzana, Gaković, Biljana M., Kovač, Janez, Panjan, Peter, Stratakis, Emmanuel, Trtica, Milan, Fotakis, C., Jelenković, Branislav, "Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure" in Journal of Materials Science, 49, no. 22 (2014):7900-7907,
https://doi.org/10.1007/s10853-014-8502-y . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Salatić, Branislav
AU  - Bogdanović-Radović, Ivančica
AU  - Panjan, Peter
AU  - Gaković, Biljana M.
AU  - Pantelić, Dejan
AU  - Trtica, Milan
AU  - Jelenković, Branislav
PY  - 2013
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5661
AB  - A study of morphological and composition changes of the (8(Al/Ti)/Si) system induced by laser pulses in different ambient conditions is presented. The effects of an Er, Yb, Cr-Glass laser, operating at 1540 nm wavelength with pulse duration of 44 ns, on a complex target were investigated. Irradiation of 8(Al/Ti)/Si was carried out at intensities of 5.9 and 9.5 x 10(11) W m(-2) in air, water and ethanol. The laser-induced morphological and composition modifications have shown dependence on applied intensities, number of laser pulses and ambient conditions. The following morphological changes were observed: (i) intense surface melting of the thin film and Si-substrate; (ii) ablation/exfoliation of the 8(Al/Ti) multilayer thin film from Si, (iii) appearance of hydrodynamic features such as resolidified material, and (iv) formation of crater at multi-pulse action. The formation of parallel periodic surface structure was only occurring in single pulse air-assisted modification. Analysis of the composition revealed that laser modification induced intermixing between the components of individual Al and Ti layers with potential formation of AlTi intermetallic compounds. (C) 2013 Elsevier Ltd. All rights reserved.
T2  - Optics and Laser Technology
T1  - Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions
VL  - 54
SP  - 22
EP  - 29
DO  - 10.1016/j.optlastec.2013.04.030
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Salatić, Branislav and Bogdanović-Radović, Ivančica and Panjan, Peter and Gaković, Biljana M. and Pantelić, Dejan and Trtica, Milan and Jelenković, Branislav",
year = "2013",
abstract = "A study of morphological and composition changes of the (8(Al/Ti)/Si) system induced by laser pulses in different ambient conditions is presented. The effects of an Er, Yb, Cr-Glass laser, operating at 1540 nm wavelength with pulse duration of 44 ns, on a complex target were investigated. Irradiation of 8(Al/Ti)/Si was carried out at intensities of 5.9 and 9.5 x 10(11) W m(-2) in air, water and ethanol. The laser-induced morphological and composition modifications have shown dependence on applied intensities, number of laser pulses and ambient conditions. The following morphological changes were observed: (i) intense surface melting of the thin film and Si-substrate; (ii) ablation/exfoliation of the 8(Al/Ti) multilayer thin film from Si, (iii) appearance of hydrodynamic features such as resolidified material, and (iv) formation of crater at multi-pulse action. The formation of parallel periodic surface structure was only occurring in single pulse air-assisted modification. Analysis of the composition revealed that laser modification induced intermixing between the components of individual Al and Ti layers with potential formation of AlTi intermetallic compounds. (C) 2013 Elsevier Ltd. All rights reserved.",
journal = "Optics and Laser Technology",
title = "Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions",
volume = "54",
pages = "22-29",
doi = "10.1016/j.optlastec.2013.04.030"
}

Petrović, S., Peruško, D., Salatić, B., Bogdanović-Radović, I., Panjan, P., Gaković, B. M., Pantelić, D., Trtica, M.,& Jelenković, B.. (2013). Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions. in Optics and Laser Technology, 54, 22-29.
https://doi.org/10.1016/j.optlastec.2013.04.030

Petrović S, Peruško D, Salatić B, Bogdanović-Radović I, Panjan P, Gaković BM, Pantelić D, Trtica M, Jelenković B. Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions. in Optics and Laser Technology. 2013;54:22-29.
doi:10.1016/j.optlastec.2013.04.030 .

Petrović, Suzana, Peruško, Davor, Salatić, Branislav, Bogdanović-Radović, Ivančica, Panjan, Peter, Gaković, Biljana M., Pantelić, Dejan, Trtica, Milan, Jelenković, Branislav, "Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions" in Optics and Laser Technology, 54 (2013):22-29,
https://doi.org/10.1016/j.optlastec.2013.04.030 . .

TY  - JOUR
AU  - Momčilović, Miloš
AU  - Limpouch, Jiri
AU  - Kmetik, V.
AU  - Redaelli, R.
AU  - Savović, Jelena
AU  - Batani, Dimitri
AU  - Stašić, Jelena
AU  - Panjan, Peter
AU  - Trtica, Milan
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4939
AB  - A study of copper target surface modification with high intensity (10(15)W/cm(2), fluence of similar to 300 J/cm(2)) Ti:sapphire laser, operating at 800 nm wavelength and pulse duration of 60 fs is presented. The Cu surface variations were studied in vacuum ambience. The copper target specific surface changes and phenomena observed are: (i) creation of craters (with extra-low diameters); (ii) formation of periodic surface structures especially expressed at the reduced intensity; (iii) presence of the clean surface in the irradiated zone (mainly absence of the oxide(s)), and (iv) occurrence of plasma in front the surface, emitting predominantly X-ray radiation (soft and hard). It can be concluded from this study that the reported laser intensities can effectively be applied for copper surface modification. The appearance of plasma in front of the target, irradiating in the X-ray/UV region, offers additional effect of surface purification facilitating contaminant-free conditions which is highly important for specific applications, e.g. in microelectronics. Generally, femtosecond laser surface modification of copper is non-contact and very rapid compared to traditional modification methods. (C) 2012 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Surface modification of copper using high intensity, 10(15)W/cm(2), femtosecond laser in vacuum
VL  - 258
IS  - 22
SP  - 8908
EP  - 8914
DO  - 10.1016/j.apsusc.2012.05.113
ER  - 

@article{
author = "Momčilović, Miloš and Limpouch, Jiri and Kmetik, V. and Redaelli, R. and Savović, Jelena and Batani, Dimitri and Stašić, Jelena and Panjan, Peter and Trtica, Milan",
year = "2012",
abstract = "A study of copper target surface modification with high intensity (10(15)W/cm(2), fluence of similar to 300 J/cm(2)) Ti:sapphire laser, operating at 800 nm wavelength and pulse duration of 60 fs is presented. The Cu surface variations were studied in vacuum ambience. The copper target specific surface changes and phenomena observed are: (i) creation of craters (with extra-low diameters); (ii) formation of periodic surface structures especially expressed at the reduced intensity; (iii) presence of the clean surface in the irradiated zone (mainly absence of the oxide(s)), and (iv) occurrence of plasma in front the surface, emitting predominantly X-ray radiation (soft and hard). It can be concluded from this study that the reported laser intensities can effectively be applied for copper surface modification. The appearance of plasma in front of the target, irradiating in the X-ray/UV region, offers additional effect of surface purification facilitating contaminant-free conditions which is highly important for specific applications, e.g. in microelectronics. Generally, femtosecond laser surface modification of copper is non-contact and very rapid compared to traditional modification methods. (C) 2012 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Surface modification of copper using high intensity, 10(15)W/cm(2), femtosecond laser in vacuum",
volume = "258",
number = "22",
pages = "8908-8914",
doi = "10.1016/j.apsusc.2012.05.113"
}

Momčilović, M., Limpouch, J., Kmetik, V., Redaelli, R., Savović, J., Batani, D., Stašić, J., Panjan, P.,& Trtica, M.. (2012). Surface modification of copper using high intensity, 10(15)W/cm(2), femtosecond laser in vacuum. in Applied Surface Science, 258(22), 8908-8914.
https://doi.org/10.1016/j.apsusc.2012.05.113

Momčilović M, Limpouch J, Kmetik V, Redaelli R, Savović J, Batani D, Stašić J, Panjan P, Trtica M. Surface modification of copper using high intensity, 10(15)W/cm(2), femtosecond laser in vacuum. in Applied Surface Science. 2012;258(22):8908-8914.
doi:10.1016/j.apsusc.2012.05.113 .

Momčilović, Miloš, Limpouch, Jiri, Kmetik, V., Redaelli, R., Savović, Jelena, Batani, Dimitri, Stašić, Jelena, Panjan, Peter, Trtica, Milan, "Surface modification of copper using high intensity, 10(15)W/cm(2), femtosecond laser in vacuum" in Applied Surface Science, 258, no. 22 (2012):8908-8914,
https://doi.org/10.1016/j.apsusc.2012.05.113 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Radak, Bojan
AU  - Radu, C.
AU  - Zamfirescu, M.
AU  - Trtica, Milan
AU  - Petrović, Suzana
AU  - Stašić, Jelena
AU  - Panjan, Peter
AU  - Mihailescu, Ion N.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4993
AB  - We studied surface modification of a double layer protective coating on steel induced by single fs laser pulse irradiation in ambient air. The outer alumina (Al2O3) layer, which protects against aggressive environments, was 1.7 mu m thick and the titanium aluminum nitride (TiAlN) layer in contact with the steel surface had a thickness of 1.9 mu m. The pulses (lambda=775 nm, tau=200 fs) were generated by a Ti:sapphire laser source. The pulse energy was varied from 0.32 mu J to 50 mu J, corresponding to an incident laser fluence of 0.11 J cm(-2) to 16.47 J cm(-2). The surface damage threshold was found to be 0.20 J cm(-2) and the alumina layer removal was initiated at 0.56 J cm(-2). This selective ablation of alumina was possible in a wide range of fluences, up to the maximum applied, without ablating the TiAlN layer beneath. (C) 2012 Elsevier B.V. All rights reserved.
T2  - Surface and Coatings Technology
T1  - Selective single pulse femtosecond laser removal of alumina (Al2O3) from a bilayered Al2O3/TiAlN/steel coating
VL  - 206
IS  - 24
SP  - 5080
EP  - 5084
DO  - 10.1016/j.surfcoat.2012.06.021
ER  - 

@article{
author = "Gaković, Biljana M. and Radak, Bojan and Radu, C. and Zamfirescu, M. and Trtica, Milan and Petrović, Suzana and Stašić, Jelena and Panjan, Peter and Mihailescu, Ion N.",
year = "2012",
abstract = "We studied surface modification of a double layer protective coating on steel induced by single fs laser pulse irradiation in ambient air. The outer alumina (Al2O3) layer, which protects against aggressive environments, was 1.7 mu m thick and the titanium aluminum nitride (TiAlN) layer in contact with the steel surface had a thickness of 1.9 mu m. The pulses (lambda=775 nm, tau=200 fs) were generated by a Ti:sapphire laser source. The pulse energy was varied from 0.32 mu J to 50 mu J, corresponding to an incident laser fluence of 0.11 J cm(-2) to 16.47 J cm(-2). The surface damage threshold was found to be 0.20 J cm(-2) and the alumina layer removal was initiated at 0.56 J cm(-2). This selective ablation of alumina was possible in a wide range of fluences, up to the maximum applied, without ablating the TiAlN layer beneath. (C) 2012 Elsevier B.V. All rights reserved.",
journal = "Surface and Coatings Technology",
title = "Selective single pulse femtosecond laser removal of alumina (Al2O3) from a bilayered Al2O3/TiAlN/steel coating",
volume = "206",
number = "24",
pages = "5080-5084",
doi = "10.1016/j.surfcoat.2012.06.021"
}

Gaković, B. M., Radak, B., Radu, C., Zamfirescu, M., Trtica, M., Petrović, S., Stašić, J., Panjan, P.,& Mihailescu, I. N.. (2012). Selective single pulse femtosecond laser removal of alumina (Al2O3) from a bilayered Al2O3/TiAlN/steel coating. in Surface and Coatings Technology, 206(24), 5080-5084.
https://doi.org/10.1016/j.surfcoat.2012.06.021

Gaković BM, Radak B, Radu C, Zamfirescu M, Trtica M, Petrović S, Stašić J, Panjan P, Mihailescu IN. Selective single pulse femtosecond laser removal of alumina (Al2O3) from a bilayered Al2O3/TiAlN/steel coating. in Surface and Coatings Technology. 2012;206(24):5080-5084.
doi:10.1016/j.surfcoat.2012.06.021 .

Gaković, Biljana M., Radak, Bojan, Radu, C., Zamfirescu, M., Trtica, Milan, Petrović, Suzana, Stašić, Jelena, Panjan, Peter, Mihailescu, Ion N., "Selective single pulse femtosecond laser removal of alumina (Al2O3) from a bilayered Al2O3/TiAlN/steel coating" in Surface and Coatings Technology, 206, no. 24 (2012):5080-5084,
https://doi.org/10.1016/j.surfcoat.2012.06.021 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Radu, C.
AU  - Zamfirescu, M.
AU  - Radak, Bojan
AU  - Trtica, Milan
AU  - Petrović, Suzana
AU  - Panjan, Peter
AU  - Zupanic, F.
AU  - Ristoscu, Carmen
AU  - Mihailescu, Ion N.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4501
AB  - A target of multilayered TiAlN/TiN coating deposited on steel was irradiated by 200 fs pulses of a Ti:Sapphire laser, operating at 775 nm. Laser fluences of 1.16 J cm(-2) to 116 J cm(-2) produced a range of modifications, from well defined parallel surface structures on the coating, to deep craters in the substrate. Parameters for coating ablation were determined in terms of laser fluence and pulse count. A single-pulse damage threshold was found to be 0.66 J cm(-2) and the damage incubation factor 0.642. At lower laser fluences formation of laser induced parallel surface structures was evident, beginning from the first pulse, with a periodicity of about 580 nm. These structures remained and were pronounced at the rim of the damage spot even when the coating was completely ablated in the centre. (C) 2011 Elsevier B.V. All rights reserved.
T2  - Surface and Coatings Technology
T1  - Femtosecond laser modification of multilayered TiAlN/TiN coating
VL  - 206
IS  - 2-3
SP  - 411
EP  - 416
DO  - 10.1016/j.surfcoat.2011.07.042
ER  - 

@article{
author = "Gaković, Biljana M. and Radu, C. and Zamfirescu, M. and Radak, Bojan and Trtica, Milan and Petrović, Suzana and Panjan, Peter and Zupanic, F. and Ristoscu, Carmen and Mihailescu, Ion N.",
year = "2011",
abstract = "A target of multilayered TiAlN/TiN coating deposited on steel was irradiated by 200 fs pulses of a Ti:Sapphire laser, operating at 775 nm. Laser fluences of 1.16 J cm(-2) to 116 J cm(-2) produced a range of modifications, from well defined parallel surface structures on the coating, to deep craters in the substrate. Parameters for coating ablation were determined in terms of laser fluence and pulse count. A single-pulse damage threshold was found to be 0.66 J cm(-2) and the damage incubation factor 0.642. At lower laser fluences formation of laser induced parallel surface structures was evident, beginning from the first pulse, with a periodicity of about 580 nm. These structures remained and were pronounced at the rim of the damage spot even when the coating was completely ablated in the centre. (C) 2011 Elsevier B.V. All rights reserved.",
journal = "Surface and Coatings Technology",
title = "Femtosecond laser modification of multilayered TiAlN/TiN coating",
volume = "206",
number = "2-3",
pages = "411-416",
doi = "10.1016/j.surfcoat.2011.07.042"
}

Gaković, B. M., Radu, C., Zamfirescu, M., Radak, B., Trtica, M., Petrović, S., Panjan, P., Zupanic, F., Ristoscu, C.,& Mihailescu, I. N.. (2011). Femtosecond laser modification of multilayered TiAlN/TiN coating. in Surface and Coatings Technology, 206(2-3), 411-416.
https://doi.org/10.1016/j.surfcoat.2011.07.042

Gaković BM, Radu C, Zamfirescu M, Radak B, Trtica M, Petrović S, Panjan P, Zupanic F, Ristoscu C, Mihailescu IN. Femtosecond laser modification of multilayered TiAlN/TiN coating. in Surface and Coatings Technology. 2011;206(2-3):411-416.
doi:10.1016/j.surfcoat.2011.07.042 .

Gaković, Biljana M., Radu, C., Zamfirescu, M., Radak, Bojan, Trtica, Milan, Petrović, Suzana, Panjan, Peter, Zupanic, F., Ristoscu, Carmen, Mihailescu, Ion N., "Femtosecond laser modification of multilayered TiAlN/TiN coating" in Surface and Coatings Technology, 206, no. 2-3 (2011):411-416,
https://doi.org/10.1016/j.surfcoat.2011.07.042 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Milovanović, Dubravka S.
AU  - Kovač, Janez
AU  - Čekada, Miha
AU  - Panjan, Peter
AU  - Gaković, Biljana M.
AU  - Trtica, Milan
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4044
AB  - A study of morphological and composition changes of the WTi/Si system induced by nanosecond and picosecond laser pulses is presented. A 190 nm thick WTi film was deposited on a silicon substrate of n-type (100). The pulsed laser systems used were: nanosecond TEA CO(2) laser (emission, 10.6 mu m; pulse FWHM; pulse duration 120 ns) and picosecond Nd:YAG laser (emission, 532 nm; pulse FWHM; pulse duration 40 ps). During experiments the used fluences (Phi) had similar values, Phi(1) = 20 J cm(-2) in case of the TEA CO(2) laser and Phi(2) = 16 J cm(-2) for the Nd: YAG laser. The laser-induced morphological and composition modifications showed a dependence on pulse duration. Generally, the following morphological changes were observed: (i) ablation/exfoliation of the WTi thin film, (ii) appearance of hydrodynamic features such as resolidified material, and (iii) formation of nano-sized grains and globules. Overall morphological modifications were more pronounced after the picosecond laser action. The surface composition analysis showed a quite different distribution of sample components depending on the pulse duration. Formation of the silicon dioxide (SiO(2)) was recorded only in the case of irradiation of the WTi/Si system by picosecond laser pulses.
T2  - Journal of Optics
T1  - Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate
VL  - 12
IS  - 7
DO  - 10.1088/2040-8978/12/7/075602
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Milovanović, Dubravka S. and Kovač, Janez and Čekada, Miha and Panjan, Peter and Gaković, Biljana M. and Trtica, Milan",
year = "2010",
abstract = "A study of morphological and composition changes of the WTi/Si system induced by nanosecond and picosecond laser pulses is presented. A 190 nm thick WTi film was deposited on a silicon substrate of n-type (100). The pulsed laser systems used were: nanosecond TEA CO(2) laser (emission, 10.6 mu m; pulse FWHM; pulse duration 120 ns) and picosecond Nd:YAG laser (emission, 532 nm; pulse FWHM; pulse duration 40 ps). During experiments the used fluences (Phi) had similar values, Phi(1) = 20 J cm(-2) in case of the TEA CO(2) laser and Phi(2) = 16 J cm(-2) for the Nd: YAG laser. The laser-induced morphological and composition modifications showed a dependence on pulse duration. Generally, the following morphological changes were observed: (i) ablation/exfoliation of the WTi thin film, (ii) appearance of hydrodynamic features such as resolidified material, and (iii) formation of nano-sized grains and globules. Overall morphological modifications were more pronounced after the picosecond laser action. The surface composition analysis showed a quite different distribution of sample components depending on the pulse duration. Formation of the silicon dioxide (SiO(2)) was recorded only in the case of irradiation of the WTi/Si system by picosecond laser pulses.",
journal = "Journal of Optics",
title = "Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate",
volume = "12",
number = "7",
doi = "10.1088/2040-8978/12/7/075602"
}

Petrović, S., Peruško, D., Milovanović, D. S., Kovač, J., Čekada, M., Panjan, P., Gaković, B. M.,& Trtica, M.. (2010). Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate. in Journal of Optics, 12(7).
https://doi.org/10.1088/2040-8978/12/7/075602

Petrović S, Peruško D, Milovanović DS, Kovač J, Čekada M, Panjan P, Gaković BM, Trtica M. Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate. in Journal of Optics. 2010;12(7).
doi:10.1088/2040-8978/12/7/075602 .

Petrović, Suzana, Peruško, Davor, Milovanović, Dubravka S., Kovač, Janez, Čekada, Miha, Panjan, Peter, Gaković, Biljana M., Trtica, Milan, "Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate" in Journal of Optics, 12, no. 7 (2010),
https://doi.org/10.1088/2040-8978/12/7/075602 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Peruško, Davor
AU  - Radak, Bojan
AU  - Desai, T.
AU  - Kovač, Janez
AU  - Panjan, Peter
AU  - Trtica, Milan
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3891
AB  - Picosecond (40 ps) pulsed Nd:YAG laser irradiation of a WTi thin film on silicon with a wavelength of 532 nm and a fluence 2.1 J/cm(2) was performed in air. This led to significant changes of the chemical composition and morphology on the surface of the WTi thin film. The results show an increase in surface roughness, due to formation of conical structures, about 50 nm wide in the base, and a very thin oxide layer composed of WO(3) and TiO(2), with a dominant TiO(2) phase at the top, within the depth of about 20 nm. The thickness of the oxide layer was dependent on the number of laser pulses. The samples were analyzed by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy.
T2  - Applied Physics. A: Materials Science and Processing
T1  - Composition and structure modification of a WTi/Si system by short laser pulses
VL  - 98
IS  - 4
SP  - 843
EP  - 847
DO  - 10.1007/s00339-010-5549-8
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Peruško, Davor and Radak, Bojan and Desai, T. and Kovač, Janez and Panjan, Peter and Trtica, Milan",
year = "2010",
abstract = "Picosecond (40 ps) pulsed Nd:YAG laser irradiation of a WTi thin film on silicon with a wavelength of 532 nm and a fluence 2.1 J/cm(2) was performed in air. This led to significant changes of the chemical composition and morphology on the surface of the WTi thin film. The results show an increase in surface roughness, due to formation of conical structures, about 50 nm wide in the base, and a very thin oxide layer composed of WO(3) and TiO(2), with a dominant TiO(2) phase at the top, within the depth of about 20 nm. The thickness of the oxide layer was dependent on the number of laser pulses. The samples were analyzed by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy.",
journal = "Applied Physics. A: Materials Science and Processing",
title = "Composition and structure modification of a WTi/Si system by short laser pulses",
volume = "98",
number = "4",
pages = "843-847",
doi = "10.1007/s00339-010-5549-8"
}

Petrović, S., Gaković, B. M., Peruško, D., Radak, B., Desai, T., Kovač, J., Panjan, P.,& Trtica, M.. (2010). Composition and structure modification of a WTi/Si system by short laser pulses. in Applied Physics. A: Materials Science and Processing, 98(4), 843-847.
https://doi.org/10.1007/s00339-010-5549-8

Petrović S, Gaković BM, Peruško D, Radak B, Desai T, Kovač J, Panjan P, Trtica M. Composition and structure modification of a WTi/Si system by short laser pulses. in Applied Physics. A: Materials Science and Processing. 2010;98(4):843-847.
doi:10.1007/s00339-010-5549-8 .

Petrović, Suzana, Gaković, Biljana M., Peruško, Davor, Radak, Bojan, Desai, T., Kovač, Janez, Panjan, Peter, Trtica, Milan, "Composition and structure modification of a WTi/Si system by short laser pulses" in Applied Physics. A: Materials Science and Processing, 98, no. 4 (2010):843-847,
https://doi.org/10.1007/s00339-010-5549-8 . .

TY  - JOUR
AU  - Stašić, Jelena
AU  - Trtica, Milan
AU  - Gaković, Biljana M.
AU  - Petrović, Suzana
AU  - Batani, Dimitri
AU  - Desai, T.
AU  - Panjan, Peter
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3621
AB  - Interaction of Nd:YAG laser, operating at 1064 or 532 nm wavelength and a pulse duration of 40 ps, with AISI 1045 steel was studied. Surface damage thresholds were estimated to be 0.30 and 0.16 J/cm(2) at the wavelengths of 1064 and 532 nm, respectively. The steel surface modi. cation was studied at the laser energy density of 10.3 J/cm(2) (at 1064 nm) and 5.4 J/cm(2) (at 532 nm). The energy absorbed from Nd: YAG laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following AISI 1045 steel surface morphological changes and processes were observed: (i) both laser wavelengths cause damage of the steel in the central zone of irradiated area; (ii) appearance of a hydrodynamic feature in the form of resolidified droplets of the material in the surrounding outer zone with 1064 nm laser wavelength; (iii) appearance of periodic surface structures, at micro- and nano-level, with the 532 nm wavelength and, (iv) development of plasma in front of the target. Generally, interaction of laser beam with the AISI 1045 steel (at 1064 and 532 nm) results in a near-instantaneous creation of damage, meaning that large steel surfaces can be processed in short time. (C) 2008 Elsevier B. V. All rights reserved.
T2  - Applied Surface Science
T1  - Surface modifications of AISI 1045 steel created by high intensity 1064 and 532 nm picosecond Nd:YAG laser pulses
VL  - 255
IS  - 8
SP  - 4474
EP  - 4478
DO  - 10.1016/j.apsusc.2008.11.049
ER  - 

@article{
author = "Stašić, Jelena and Trtica, Milan and Gaković, Biljana M. and Petrović, Suzana and Batani, Dimitri and Desai, T. and Panjan, Peter",
year = "2009",
abstract = "Interaction of Nd:YAG laser, operating at 1064 or 532 nm wavelength and a pulse duration of 40 ps, with AISI 1045 steel was studied. Surface damage thresholds were estimated to be 0.30 and 0.16 J/cm(2) at the wavelengths of 1064 and 532 nm, respectively. The steel surface modi. cation was studied at the laser energy density of 10.3 J/cm(2) (at 1064 nm) and 5.4 J/cm(2) (at 532 nm). The energy absorbed from Nd: YAG laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following AISI 1045 steel surface morphological changes and processes were observed: (i) both laser wavelengths cause damage of the steel in the central zone of irradiated area; (ii) appearance of a hydrodynamic feature in the form of resolidified droplets of the material in the surrounding outer zone with 1064 nm laser wavelength; (iii) appearance of periodic surface structures, at micro- and nano-level, with the 532 nm wavelength and, (iv) development of plasma in front of the target. Generally, interaction of laser beam with the AISI 1045 steel (at 1064 and 532 nm) results in a near-instantaneous creation of damage, meaning that large steel surfaces can be processed in short time. (C) 2008 Elsevier B. V. All rights reserved.",
journal = "Applied Surface Science",
title = "Surface modifications of AISI 1045 steel created by high intensity 1064 and 532 nm picosecond Nd:YAG laser pulses",
volume = "255",
number = "8",
pages = "4474-4478",
doi = "10.1016/j.apsusc.2008.11.049"
}

Stašić, J., Trtica, M., Gaković, B. M., Petrović, S., Batani, D., Desai, T.,& Panjan, P.. (2009). Surface modifications of AISI 1045 steel created by high intensity 1064 and 532 nm picosecond Nd:YAG laser pulses. in Applied Surface Science, 255(8), 4474-4478.
https://doi.org/10.1016/j.apsusc.2008.11.049

Stašić J, Trtica M, Gaković BM, Petrović S, Batani D, Desai T, Panjan P. Surface modifications of AISI 1045 steel created by high intensity 1064 and 532 nm picosecond Nd:YAG laser pulses. in Applied Surface Science. 2009;255(8):4474-4478.
doi:10.1016/j.apsusc.2008.11.049 .

Stašić, Jelena, Trtica, Milan, Gaković, Biljana M., Petrović, Suzana, Batani, Dimitri, Desai, T., Panjan, Peter, "Surface modifications of AISI 1045 steel created by high intensity 1064 and 532 nm picosecond Nd:YAG laser pulses" in Applied Surface Science, 255, no. 8 (2009):4474-4478,
https://doi.org/10.1016/j.apsusc.2008.11.049 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Trtica, Milan
AU  - Radak, Bojan
AU  - Petrović, Suzana
AU  - Panjan, Peter
AU  - Čekada, Miha
AU  - Desai, T.
AU  - Batani, Dimitri
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3615
AB  - A multilayered TiAlN/TiN coating deposited on H11 work-steel was irradiated by a TEA CO(2) laser (ns pulses) and a Nd:YAG laser (ps pulses), and the effects compared. The coating was 2.17 mu m thick and consisted of 45 layers. The laser-induced modifications showed dependence on laser pulse duration, pulse count and laser wavelength. The conditions for coating ablation in both cases were determined. The experiment has revealed laser-induced periodic surface structures (LPSS) on nanometre and micrometre scales, depending on the laser wavelength used. Sample surfaces were characterized before and after laser irradiation by an optical microscope, scanning electron microscope (SEM), focused ion beam (FIB) microscope and profilometry.
T2  - Journal of Optics. A: Pure and Applied Optics
T1  - Modification of multilayered TiAlN/TiN coating by nanosecond and picosecond laser pulses
VL  - 11
IS  - 1
DO  - 10.1088/1464-4258/11/1/015601
ER  - 

@article{
author = "Gaković, Biljana M. and Trtica, Milan and Radak, Bojan and Petrović, Suzana and Panjan, Peter and Čekada, Miha and Desai, T. and Batani, Dimitri",
year = "2009",
abstract = "A multilayered TiAlN/TiN coating deposited on H11 work-steel was irradiated by a TEA CO(2) laser (ns pulses) and a Nd:YAG laser (ps pulses), and the effects compared. The coating was 2.17 mu m thick and consisted of 45 layers. The laser-induced modifications showed dependence on laser pulse duration, pulse count and laser wavelength. The conditions for coating ablation in both cases were determined. The experiment has revealed laser-induced periodic surface structures (LPSS) on nanometre and micrometre scales, depending on the laser wavelength used. Sample surfaces were characterized before and after laser irradiation by an optical microscope, scanning electron microscope (SEM), focused ion beam (FIB) microscope and profilometry.",
journal = "Journal of Optics. A: Pure and Applied Optics",
title = "Modification of multilayered TiAlN/TiN coating by nanosecond and picosecond laser pulses",
volume = "11",
number = "1",
doi = "10.1088/1464-4258/11/1/015601"
}

Gaković, B. M., Trtica, M., Radak, B., Petrović, S., Panjan, P., Čekada, M., Desai, T.,& Batani, D.. (2009). Modification of multilayered TiAlN/TiN coating by nanosecond and picosecond laser pulses. in Journal of Optics. A: Pure and Applied Optics, 11(1).
https://doi.org/10.1088/1464-4258/11/1/015601

Gaković BM, Trtica M, Radak B, Petrović S, Panjan P, Čekada M, Desai T, Batani D. Modification of multilayered TiAlN/TiN coating by nanosecond and picosecond laser pulses. in Journal of Optics. A: Pure and Applied Optics. 2009;11(1).
doi:10.1088/1464-4258/11/1/015601 .

Gaković, Biljana M., Trtica, Milan, Radak, Bojan, Petrović, Suzana, Panjan, Peter, Čekada, Miha, Desai, T., Batani, Dimitri, "Modification of multilayered TiAlN/TiN coating by nanosecond and picosecond laser pulses" in Journal of Optics. A: Pure and Applied Optics, 11, no. 1 (2009),
https://doi.org/10.1088/1464-4258/11/1/015601 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Peruško, Davor
AU  - Trtica, Milan
AU  - Radak, Bojan
AU  - Panjan, Peter
AU  - Miljanić, Šćepan S.
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3431
AB  - Interaction of a nanosecond transversely excited atmospheric (TEA) CO2 laser, operating at 10.6 mm, with tungsten-titanium thin film (190 nm) deposited on silicon of n-type (1 0 0) orientation, was studied. Multi-pulse irradiation was performed in air atmosphere with laser energy densities in the range 24-49 J/cm(2). The energy absorbed from the laser beam was mainly converted to thermal energy, which generated a series of effects. The following morphological changes were observed: (i) partial ablation/exfoliation of the WTi thin film, (ii) partial modification of the silicon substrate with formation of polygonal grains, (iii) appearance of hydrodynamic features including nano-globules. Torch-like plumes started appearing in front of the target after several laser pulses. (C) 2007 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses
VL  - 254
IS  - 13
SP  - 4013
EP  - 4017
DO  - 10.1016/j.apsusc.2007.12.041
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Peruško, Davor and Trtica, Milan and Radak, Bojan and Panjan, Peter and Miljanić, Šćepan S.",
year = "2008",
abstract = "Interaction of a nanosecond transversely excited atmospheric (TEA) CO2 laser, operating at 10.6 mm, with tungsten-titanium thin film (190 nm) deposited on silicon of n-type (1 0 0) orientation, was studied. Multi-pulse irradiation was performed in air atmosphere with laser energy densities in the range 24-49 J/cm(2). The energy absorbed from the laser beam was mainly converted to thermal energy, which generated a series of effects. The following morphological changes were observed: (i) partial ablation/exfoliation of the WTi thin film, (ii) partial modification of the silicon substrate with formation of polygonal grains, (iii) appearance of hydrodynamic features including nano-globules. Torch-like plumes started appearing in front of the target after several laser pulses. (C) 2007 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses",
volume = "254",
number = "13",
pages = "4013-4017",
doi = "10.1016/j.apsusc.2007.12.041"
}

Petrović, S., Gaković, B. M., Peruško, D., Trtica, M., Radak, B., Panjan, P.,& Miljanić, Š. S.. (2008). Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses. in Applied Surface Science, 254(13), 4013-4017.
https://doi.org/10.1016/j.apsusc.2007.12.041

Petrović S, Gaković BM, Peruško D, Trtica M, Radak B, Panjan P, Miljanić ŠS. Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses. in Applied Surface Science. 2008;254(13):4013-4017.
doi:10.1016/j.apsusc.2007.12.041 .

Petrović, Suzana, Gaković, Biljana M., Peruško, Davor, Trtica, Milan, Radak, Bojan, Panjan, Peter, Miljanić, Šćepan S., "Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses" in Applied Surface Science, 254, no. 13 (2008):4013-4017,
https://doi.org/10.1016/j.apsusc.2007.12.041 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Trtica, Milan
AU  - Batani, Dimitri
AU  - Desai, T.
AU  - Panjan, Peter
AU  - Vasiljević-Radović, Dana
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6581
AB  - The interaction of a picosecond Nd: YAG laser ( wavelength 532 nm, pulse duration 40 ps) with a polycrystalline titanium nitride ( TiN) film was studied. The TiN thin film was deposited by physical vapour deposition on a silicon substrate. The titanium nitride/ silicon system was modified with an energy fluence from 0.2 to 5.9 J cm(-2). Multi- pulse irradiation was performed in air by a focused laser beam. Surface modifications were analysed after 1 - 100 successive laser pulses. Depending on the laser pulse energy and pulse count, the following phenomena were observed: ( i) increased surface roughness, ( ii) titanium nitride film cracking, ( iii) silicon substrate modification, ( iv) film exfoliation and ( v) laser- induced periodical surface structures on nano- ( NPSS) and micro- dimensions ( MPSS).
T2  - Journal of Optics. A: Pure and Applied Optics
T1  - Surface modification of titanium nitride film by a picosecond Nd : YAG laser
VL  - 9
IS  - 6
SP  - S76
EP  - S80
DO  - 10.1088/1464-4258/9/6/S11
ER  - 

@article{
author = "Gaković, Biljana M. and Trtica, Milan and Batani, Dimitri and Desai, T. and Panjan, Peter and Vasiljević-Radović, Dana",
year = "2007",
abstract = "The interaction of a picosecond Nd: YAG laser ( wavelength 532 nm, pulse duration 40 ps) with a polycrystalline titanium nitride ( TiN) film was studied. The TiN thin film was deposited by physical vapour deposition on a silicon substrate. The titanium nitride/ silicon system was modified with an energy fluence from 0.2 to 5.9 J cm(-2). Multi- pulse irradiation was performed in air by a focused laser beam. Surface modifications were analysed after 1 - 100 successive laser pulses. Depending on the laser pulse energy and pulse count, the following phenomena were observed: ( i) increased surface roughness, ( ii) titanium nitride film cracking, ( iii) silicon substrate modification, ( iv) film exfoliation and ( v) laser- induced periodical surface structures on nano- ( NPSS) and micro- dimensions ( MPSS).",
journal = "Journal of Optics. A: Pure and Applied Optics",
title = "Surface modification of titanium nitride film by a picosecond Nd : YAG laser",
volume = "9",
number = "6",
pages = "S76-S80",
doi = "10.1088/1464-4258/9/6/S11"
}

Gaković, B. M., Trtica, M., Batani, D., Desai, T., Panjan, P.,& Vasiljević-Radović, D.. (2007). Surface modification of titanium nitride film by a picosecond Nd : YAG laser. in Journal of Optics. A: Pure and Applied Optics, 9(6), S76-S80.
https://doi.org/10.1088/1464-4258/9/6/S11

Gaković BM, Trtica M, Batani D, Desai T, Panjan P, Vasiljević-Radović D. Surface modification of titanium nitride film by a picosecond Nd : YAG laser. in Journal of Optics. A: Pure and Applied Optics. 2007;9(6):S76-S80.
doi:10.1088/1464-4258/9/6/S11 .

Gaković, Biljana M., Trtica, Milan, Batani, Dimitri, Desai, T., Panjan, Peter, Vasiljević-Radović, Dana, "Surface modification of titanium nitride film by a picosecond Nd : YAG laser" in Journal of Optics. A: Pure and Applied Optics, 9, no. 6 (2007):S76-S80,
https://doi.org/10.1088/1464-4258/9/6/S11 . .

TY  - JOUR
AU  - Trtica, Milan
AU  - Gaković, Biljana M.
AU  - Batani, Dimitri
AU  - Desai, Tara
AU  - Panjan, Peter
AU  - Radak, Bojan
PY  - 2006
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3137
AB  - Interaction of an Nd:YAG laser, operating at 1064 or 532 nm wavelength and pulse duration of 40 ps, with titanium implant was studied. Surface damage thresholds were estimated to 0.9 and 0.6 J/cm(2) at wavelengths 1064 and 532 nm, respectively. The titanium implant surface modification was studied by the laser beam of energy density of 4.0 and 23.8 J/cm(2) (at 1064 nm) and 13.6 J/cm(2) (at 532 nm). The energy absorbed from the Nd:YAG laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following titanium/implant surface morphological changes were observed: (i) both laser wavelengths cause damage of the titanium in the central zone of the irradiated area, (ii) appearance of a hydrodynamic feature in the form of resolidified droplets of the material in the surrounding outer zone with the 1064 nm laser wavelength and (iii) appearance of wave-like inicrostructures with the 532 nm wavelength. Generally, both laser wavelengths and the corresponding laser energy densities can efficiently enhance the titanium/implant roughness. This implant roughness is expected to improve its bio-integration. The process of the laser interaction with titanium implant was accompanied by formation of plasma. (c) 2006 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Surface modifications of a titanium implant by a picosecond Nd : YAG laser operating at 1064 and 532 nm
VL  - 253
IS  - 5
SP  - 2551
EP  - 2556
DO  - 10.1016/j.apsusc.2006.05.024
ER  - 

@article{
author = "Trtica, Milan and Gaković, Biljana M. and Batani, Dimitri and Desai, Tara and Panjan, Peter and Radak, Bojan",
year = "2006",
abstract = "Interaction of an Nd:YAG laser, operating at 1064 or 532 nm wavelength and pulse duration of 40 ps, with titanium implant was studied. Surface damage thresholds were estimated to 0.9 and 0.6 J/cm(2) at wavelengths 1064 and 532 nm, respectively. The titanium implant surface modification was studied by the laser beam of energy density of 4.0 and 23.8 J/cm(2) (at 1064 nm) and 13.6 J/cm(2) (at 532 nm). The energy absorbed from the Nd:YAG laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following titanium/implant surface morphological changes were observed: (i) both laser wavelengths cause damage of the titanium in the central zone of the irradiated area, (ii) appearance of a hydrodynamic feature in the form of resolidified droplets of the material in the surrounding outer zone with the 1064 nm laser wavelength and (iii) appearance of wave-like inicrostructures with the 532 nm wavelength. Generally, both laser wavelengths and the corresponding laser energy densities can efficiently enhance the titanium/implant roughness. This implant roughness is expected to improve its bio-integration. The process of the laser interaction with titanium implant was accompanied by formation of plasma. (c) 2006 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Surface modifications of a titanium implant by a picosecond Nd : YAG laser operating at 1064 and 532 nm",
volume = "253",
number = "5",
pages = "2551-2556",
doi = "10.1016/j.apsusc.2006.05.024"
}

Trtica, M., Gaković, B. M., Batani, D., Desai, T., Panjan, P.,& Radak, B.. (2006). Surface modifications of a titanium implant by a picosecond Nd : YAG laser operating at 1064 and 532 nm. in Applied Surface Science, 253(5), 2551-2556.
https://doi.org/10.1016/j.apsusc.2006.05.024

Trtica M, Gaković BM, Batani D, Desai T, Panjan P, Radak B. Surface modifications of a titanium implant by a picosecond Nd : YAG laser operating at 1064 and 532 nm. in Applied Surface Science. 2006;253(5):2551-2556.
doi:10.1016/j.apsusc.2006.05.024 .

Trtica, Milan, Gaković, Biljana M., Batani, Dimitri, Desai, Tara, Panjan, Peter, Radak, Bojan, "Surface modifications of a titanium implant by a picosecond Nd : YAG laser operating at 1064 and 532 nm" in Applied Surface Science, 253, no. 5 (2006):2551-2556,
https://doi.org/10.1016/j.apsusc.2006.05.024 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Trtica, Milan
AU  - Petrović, Suzana
AU  - Panjan, Peter
AU  - Cekada, M
AU  - Samardzija, Z
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6532
AB  - The effects of TEA CO2 laser radiation on AISI 420 stainless steel and formed surface structures are studied. The laser energy density of 45.0 J/cm(2) has modified the target surface. Qualitatively, the modifications of AISI 420 steel can be summarized as follows: change of color after action of one laser pulse; central zone of interaction in crater like form and periphery zone of interaction (for more than 10 laser pulses); appearance of grainy features and ablation rate of near 4 rim per laser pulse (action of 400 laser pulses); hydrodynamical effects like resolidified rim and droplets.
T2  - Materials Science Forum
T1  - Surface structures formed on AISI 420 stainless steel by pulsed laser irradiation
VL  - 494
SP  - 309
EP  - 314
DO  - 10.4028/www.scientific.net/MSF.494.309
ER  - 

@article{
author = "Gaković, Biljana M. and Trtica, Milan and Petrović, Suzana and Panjan, Peter and Cekada, M and Samardzija, Z",
year = "2005",
abstract = "The effects of TEA CO2 laser radiation on AISI 420 stainless steel and formed surface structures are studied. The laser energy density of 45.0 J/cm(2) has modified the target surface. Qualitatively, the modifications of AISI 420 steel can be summarized as follows: change of color after action of one laser pulse; central zone of interaction in crater like form and periphery zone of interaction (for more than 10 laser pulses); appearance of grainy features and ablation rate of near 4 rim per laser pulse (action of 400 laser pulses); hydrodynamical effects like resolidified rim and droplets.",
journal = "Materials Science Forum",
title = "Surface structures formed on AISI 420 stainless steel by pulsed laser irradiation",
volume = "494",
pages = "309-314",
doi = "10.4028/www.scientific.net/MSF.494.309"
}

Gaković, B. M., Trtica, M., Petrović, S., Panjan, P., Cekada, M.,& Samardzija, Z.. (2005). Surface structures formed on AISI 420 stainless steel by pulsed laser irradiation. in Materials Science Forum, 494, 309-314.
https://doi.org/10.4028/www.scientific.net/MSF.494.309

Gaković BM, Trtica M, Petrović S, Panjan P, Cekada M, Samardzija Z. Surface structures formed on AISI 420 stainless steel by pulsed laser irradiation. in Materials Science Forum. 2005;494:309-314.
doi:10.4028/www.scientific.net/MSF.494.309 .

Gaković, Biljana M., Trtica, Milan, Petrović, Suzana, Panjan, Peter, Cekada, M, Samardzija, Z, "Surface structures formed on AISI 420 stainless steel by pulsed laser irradiation" in Materials Science Forum, 494 (2005):309-314,
https://doi.org/10.4028/www.scientific.net/MSF.494.309 . .

TY  - JOUR
AU  - Gaković, Biljana M.
AU  - Trtica, Milan
AU  - Panjan, Peter
AU  - Cekada, M
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2786
AB  - The interaction of a transversely excited atmospheric (TEA) CO2 laser with chromium oxynitride (CrON) coating deposited on a AISI 304 steel substrate was considered. The results have shown that CrON was surface-modified by the laser beam of 45 J/cm(2) energy density. The energy absorbed from the TEA CO2 laser beam was partially converted into thermal energy, which has generated a series of effects such as melting, vaporization of the molten material, and shock waves in the vapor and in the solid. Morphological manifestations on the CrON coating surface can be summarized as follows: non-uniform features with ablation and appearance of crater-like form (central zone of interaction); appearance of three damaged areas and presence of hydrodynamic effects with resolidified droplets (periphery zone of interaction). In case of applied energy density the interaction of laser radiation with CrON has been always followed by plasma creation in front of the coating.
T2  - Applied Physics. A: Materials Science and Processing
T1  - Surface modification of the Cr-based coatings by the pulsed TEA CO2 laser
VL  - 79
IS  - 4-6
SP  - 1353
EP  - 1355
DO  - 10.1007/s00339-004-2778-8
ER  - 

@article{
author = "Gaković, Biljana M. and Trtica, Milan and Panjan, Peter and Cekada, M",
year = "2004",
abstract = "The interaction of a transversely excited atmospheric (TEA) CO2 laser with chromium oxynitride (CrON) coating deposited on a AISI 304 steel substrate was considered. The results have shown that CrON was surface-modified by the laser beam of 45 J/cm(2) energy density. The energy absorbed from the TEA CO2 laser beam was partially converted into thermal energy, which has generated a series of effects such as melting, vaporization of the molten material, and shock waves in the vapor and in the solid. Morphological manifestations on the CrON coating surface can be summarized as follows: non-uniform features with ablation and appearance of crater-like form (central zone of interaction); appearance of three damaged areas and presence of hydrodynamic effects with resolidified droplets (periphery zone of interaction). In case of applied energy density the interaction of laser radiation with CrON has been always followed by plasma creation in front of the coating.",
journal = "Applied Physics. A: Materials Science and Processing",
title = "Surface modification of the Cr-based coatings by the pulsed TEA CO2 laser",
volume = "79",
number = "4-6",
pages = "1353-1355",
doi = "10.1007/s00339-004-2778-8"
}

Gaković, B. M., Trtica, M., Panjan, P.,& Cekada, M.. (2004). Surface modification of the Cr-based coatings by the pulsed TEA CO2 laser. in Applied Physics. A: Materials Science and Processing, 79(4-6), 1353-1355.
https://doi.org/10.1007/s00339-004-2778-8

Gaković BM, Trtica M, Panjan P, Cekada M. Surface modification of the Cr-based coatings by the pulsed TEA CO2 laser. in Applied Physics. A: Materials Science and Processing. 2004;79(4-6):1353-1355.
doi:10.1007/s00339-004-2778-8 .

Gaković, Biljana M., Trtica, Milan, Panjan, Peter, Cekada, M, "Surface modification of the Cr-based coatings by the pulsed TEA CO2 laser" in Applied Physics. A: Materials Science and Processing, 79, no. 4-6 (2004):1353-1355,
https://doi.org/10.1007/s00339-004-2778-8 . .