TY  - CONF
AU  - Ivić, Zoran
AU  - Nikolić, Violeta N.
AU  - Čevizović, Dalibor
AU  - Pržulj, Željko
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10968
AB  - We present an overview of the recent studies on self-induced transparency in superconducting quantum metamaterials. The realization of slow-light optical solitons and their role in quantum information storage is emphasized. © 2023 IEEE.
PB  - IEEE
C3  - InfoTeh-Jahorina : 22. međunarodni simpozijum INFOTEH-JAHORINA 202; Mart 15-17
T1  - Slow Light in Quantum Metamaterials
DO  - 10.1109/INFOTEH57020.2023.10094056
ER  - 

@conference{
author = "Ivić, Zoran and Nikolić, Violeta N. and Čevizović, Dalibor and Pržulj, Željko",
year = "2023",
abstract = "We present an overview of the recent studies on self-induced transparency in superconducting quantum metamaterials. The realization of slow-light optical solitons and their role in quantum information storage is emphasized. © 2023 IEEE.",
publisher = "IEEE",
journal = "InfoTeh-Jahorina : 22. međunarodni simpozijum INFOTEH-JAHORINA 202; Mart 15-17",
title = "Slow Light in Quantum Metamaterials",
doi = "10.1109/INFOTEH57020.2023.10094056"
}

Ivić, Z., Nikolić, V. N., Čevizović, D.,& Pržulj, Ž.. (2023). Slow Light in Quantum Metamaterials. in InfoTeh-Jahorina : 22. međunarodni simpozijum INFOTEH-JAHORINA 202; Mart 15-17
IEEE..
https://doi.org/10.1109/INFOTEH57020.2023.10094056

Ivić Z, Nikolić VN, Čevizović D, Pržulj Ž. Slow Light in Quantum Metamaterials. in InfoTeh-Jahorina : 22. međunarodni simpozijum INFOTEH-JAHORINA 202; Mart 15-17. 2023;.
doi:10.1109/INFOTEH57020.2023.10094056 .

Ivić, Zoran, Nikolić, Violeta N., Čevizović, Dalibor, Pržulj, Željko, "Slow Light in Quantum Metamaterials" in InfoTeh-Jahorina : 22. međunarodni simpozijum INFOTEH-JAHORINA 202; Mart 15-17 (2023),
https://doi.org/10.1109/INFOTEH57020.2023.10094056 . .

TY  - JOUR
AU  - Borka, Duško
AU  - Borka Jovanović, Vesna
AU  - Nikolić, Violeta N.
AU  - Lazarov, Nenad Đ.
AU  - Jovanović, Predrag
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10151
AB  - We estimate the parameters of the Hybrid Palatini gravity model with the Schwarzschild precession of S-stars, specifically of the S2, S38 and S55 stars. We also take into account the case of bulk mass distribution near the Galactic Center. We assume that the Schwarzschild orbital precession of mentioned S-stars is the same as in General Relativity (GR) in all studied cases. In 2020, the GRAVITY Collaboration detected the orbital precession of the S2 star around the supermassive black hole (SMBH) at the Galactic Center and showed that it is close to the GR prediction. The astronomical data analysis of S38 and S55 orbits showed that, also in these cases, the orbital precession is close to the GR prediction. Based on this observational fact, we evaluated the parameters of the Hybrid Palatini Gravity model with the Schwarzschild precession of the S2, S38 and S55 stars, and we estimated the range of parameters of the Hybrid Palatini gravity model for which the orbital precession is as in GR for all three stars. We also evaluated the parameters of the Hybrid Palatini Gravity model in the case of different values of bulk mass density distribution of extended matter. We believe that proposed method is a useful tool to evaluate parameters of the gravitational potential at the Galactic Center. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
T2  - Universe
T1  - Estimating the Parameters of the Hybrid Palatini Gravity Model with the Schwarzschild Precession of S2, S38 and S55 Stars: Case of Bulk Mass Distribution
VL  - 8
IS  - 2
SP  - 70
DO  - 10.3390/universe8020070
ER  - 

@article{
author = "Borka, Duško and Borka Jovanović, Vesna and Nikolić, Violeta N. and Lazarov, Nenad Đ. and Jovanović, Predrag",
year = "2022",
abstract = "We estimate the parameters of the Hybrid Palatini gravity model with the Schwarzschild precession of S-stars, specifically of the S2, S38 and S55 stars. We also take into account the case of bulk mass distribution near the Galactic Center. We assume that the Schwarzschild orbital precession of mentioned S-stars is the same as in General Relativity (GR) in all studied cases. In 2020, the GRAVITY Collaboration detected the orbital precession of the S2 star around the supermassive black hole (SMBH) at the Galactic Center and showed that it is close to the GR prediction. The astronomical data analysis of S38 and S55 orbits showed that, also in these cases, the orbital precession is close to the GR prediction. Based on this observational fact, we evaluated the parameters of the Hybrid Palatini Gravity model with the Schwarzschild precession of the S2, S38 and S55 stars, and we estimated the range of parameters of the Hybrid Palatini gravity model for which the orbital precession is as in GR for all three stars. We also evaluated the parameters of the Hybrid Palatini Gravity model in the case of different values of bulk mass density distribution of extended matter. We believe that proposed method is a useful tool to evaluate parameters of the gravitational potential at the Galactic Center. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.",
journal = "Universe",
title = "Estimating the Parameters of the Hybrid Palatini Gravity Model with the Schwarzschild Precession of S2, S38 and S55 Stars: Case of Bulk Mass Distribution",
volume = "8",
number = "2",
pages = "70",
doi = "10.3390/universe8020070"
}

Borka, D., Borka Jovanović, V., Nikolić, V. N., Lazarov, N. Đ.,& Jovanović, P.. (2022). Estimating the Parameters of the Hybrid Palatini Gravity Model with the Schwarzschild Precession of S2, S38 and S55 Stars: Case of Bulk Mass Distribution. in Universe, 8(2), 70.
https://doi.org/10.3390/universe8020070

Borka D, Borka Jovanović V, Nikolić VN, Lazarov NĐ, Jovanović P. Estimating the Parameters of the Hybrid Palatini Gravity Model with the Schwarzschild Precession of S2, S38 and S55 Stars: Case of Bulk Mass Distribution. in Universe. 2022;8(2):70.
doi:10.3390/universe8020070 .

Borka, Duško, Borka Jovanović, Vesna, Nikolić, Violeta N., Lazarov, Nenad Đ., Jovanović, Predrag, "Estimating the Parameters of the Hybrid Palatini Gravity Model with the Schwarzschild Precession of S2, S38 and S55 Stars: Case of Bulk Mass Distribution" in Universe, 8, no. 2 (2022):70,
https://doi.org/10.3390/universe8020070 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Rajnak, Michal
AU  - Mariano, Jose F. M. L.
AU  - Lazarov, Nenad Đ.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10199
AB  - The characterization of nanocomposite samples which contain Cu, Fe-species, prepared by the sol-gel method, was established by Nikolić et al., in a previous article (Nikolić et al. in Journal of Solid State Physics 513:1, 2021). In this study, the magnetic behavior of nanocomposite samples was examined. The basic parameters of the room- and low-temperature magnetic hysteresis loops are discussed. To better describe the shape of magnetic hysteresis loop, the authors proposed to consider additional parameters - measures of the exterior angles of the hysteresis curve. Behavior of hysteresis parameters and exterior angles, caused by annealing treatment, was investigated by measuring hysteresis loops at two measured temperatures: 298K, and 5K. Correlation between changes in the behavior of hysteresis parameters and exterior angles was discussed. An attempt has been made to attribute physical meaning to chosen measured angles, which would allow a better understanding of the magnetic hysteresis curve. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
T2  - Journal of Superconductivity and Novel Magnetism
T1  - Magnetic Hysteresis Loops Revisited: Step Closer to Understand the Role of Exterior Angles
VL  - 35
IS  - 5
SP  - 1353
EP  - 1373
DO  - 10.1007/s10948-021-06118-z
ER  - 

@article{
author = "Nikolić, Violeta N. and Rajnak, Michal and Mariano, Jose F. M. L. and Lazarov, Nenad Đ.",
year = "2022",
abstract = "The characterization of nanocomposite samples which contain Cu, Fe-species, prepared by the sol-gel method, was established by Nikolić et al., in a previous article (Nikolić et al. in Journal of Solid State Physics 513:1, 2021). In this study, the magnetic behavior of nanocomposite samples was examined. The basic parameters of the room- and low-temperature magnetic hysteresis loops are discussed. To better describe the shape of magnetic hysteresis loop, the authors proposed to consider additional parameters - measures of the exterior angles of the hysteresis curve. Behavior of hysteresis parameters and exterior angles, caused by annealing treatment, was investigated by measuring hysteresis loops at two measured temperatures: 298K, and 5K. Correlation between changes in the behavior of hysteresis parameters and exterior angles was discussed. An attempt has been made to attribute physical meaning to chosen measured angles, which would allow a better understanding of the magnetic hysteresis curve. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.",
journal = "Journal of Superconductivity and Novel Magnetism",
title = "Magnetic Hysteresis Loops Revisited: Step Closer to Understand the Role of Exterior Angles",
volume = "35",
number = "5",
pages = "1353-1373",
doi = "10.1007/s10948-021-06118-z"
}

Nikolić, V. N., Rajnak, M., Mariano, J. F. M. L.,& Lazarov, N. Đ.. (2022). Magnetic Hysteresis Loops Revisited: Step Closer to Understand the Role of Exterior Angles. in Journal of Superconductivity and Novel Magnetism, 35(5), 1353-1373.
https://doi.org/10.1007/s10948-021-06118-z

Nikolić VN, Rajnak M, Mariano JFML, Lazarov NĐ. Magnetic Hysteresis Loops Revisited: Step Closer to Understand the Role of Exterior Angles. in Journal of Superconductivity and Novel Magnetism. 2022;35(5):1353-1373.
doi:10.1007/s10948-021-06118-z .

Nikolić, Violeta N., Rajnak, Michal, Mariano, Jose F. M. L., Lazarov, Nenad Đ., "Magnetic Hysteresis Loops Revisited: Step Closer to Understand the Role of Exterior Angles" in Journal of Superconductivity and Novel Magnetism, 35, no. 5 (2022):1353-1373,
https://doi.org/10.1007/s10948-021-06118-z . .

TY  - CONF
AU  - Lazarov, Nenad Đ.
AU  - Nikolić, Violeta N.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11235
AB  - Рад се бави учешћем Aлександра Фридмана у теорији великог праска. Познат је по Фридмановим једначинама које описују покретни свемир, тј. свемир који може да се шири, скупља и буде статичан у зависности од параметра к (кривине), у FLRW метрици. Мада су те једначине добили и други, као што је Жорж Леметр (Georges Lemaitre), Фридман их је први добио и објавио 1922 године. Ове једначине се и данас користе за процене астрономских мерења.
AB  - In this paper, we presented the participation of Alexander Friedmann in the Big Bang Theory. He is known for his Friedmman equations which describe the dynamic cosmos, ie. it expands, shrinks, and becomes static in depends on curvature parameter k in FLRW metric. By the way, these equations are given also, by others, such as, for example, Georges Lemaitre. Friedmann have got first equations and published in 1922 year. These equations are used for assessment of astronomical measurements today.
PB  - Belgrade : Astronomical Society "Rudjer Bošković"
C3  - Зборник радова конференције “Развој астрономије код Срба XI”
T1  - Допринос Александра Фридмана теорији великог праска
T1  - The Contribution of Alexander Friedmann to the Big Bang Theory
IS  - 22
SP  - 369
EP  - 380
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11235
ER  - 

@conference{
author = "Lazarov, Nenad Đ. and Nikolić, Violeta N.",
year = "2022",
abstract = "Рад се бави учешћем Aлександра Фридмана у теорији великог праска. Познат је по Фридмановим једначинама које описују покретни свемир, тј. свемир који може да се шири, скупља и буде статичан у зависности од параметра к (кривине), у FLRW метрици. Мада су те једначине добили и други, као што је Жорж Леметр (Georges Lemaitre), Фридман их је први добио и објавио 1922 године. Ове једначине се и данас користе за процене астрономских мерења., In this paper, we presented the participation of Alexander Friedmann in the Big Bang Theory. He is known for his Friedmman equations which describe the dynamic cosmos, ie. it expands, shrinks, and becomes static in depends on curvature parameter k in FLRW metric. By the way, these equations are given also, by others, such as, for example, Georges Lemaitre. Friedmann have got first equations and published in 1922 year. These equations are used for assessment of astronomical measurements today.",
publisher = "Belgrade : Astronomical Society "Rudjer Bošković"",
journal = "Зборник радова конференције “Развој астрономије код Срба XI”",
title = "Допринос Александра Фридмана теорији великог праска, The Contribution of Alexander Friedmann to the Big Bang Theory",
number = "22",
pages = "369-380",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11235"
}

Lazarov, N. Đ.,& Nikolić, V. N.. (2022). Допринос Александра Фридмана теорији великог праска. in Зборник радова конференције “Развој астрономије код Срба XI”
Belgrade : Astronomical Society "Rudjer Bošković".(22), 369-380.
https://hdl.handle.net/21.15107/rcub_vinar_11235

Lazarov NĐ, Nikolić VN. Допринос Александра Фридмана теорији великог праска. in Зборник радова конференције “Развој астрономије код Срба XI”. 2022;(22):369-380.
https://hdl.handle.net/21.15107/rcub_vinar_11235 .

Lazarov, Nenad Đ., Nikolić, Violeta N., "Допринос Александра Фридмана теорији великог праска" in Зборник радова конференције “Развој астрономије код Срба XI”, no. 22 (2022):369-380,
https://hdl.handle.net/21.15107/rcub_vinar_11235 .

TY  - CONF
AU  - Lazarov, Nenad Đ.
AU  - Nikolić, Violeta N.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11236
AB  - Рад се бави учешћем Жоржа Леметра у теорији великог праска. Његов допринос се огледа у теорији ширења свемира, теорији великог праска и увођењу Леметрових координата. Предложио је теоретске основе свемира који се шири што је потврдио Едвин Хабл. Имао је значајно учешће у формирању Хабловог закона и први је предложио вредност Хаблове константе. Он је такође предложио модел свемира који је назвао хипотеза исконског атома или Космичко јаје.
AB  - In this paper, we represented the participation of Abbe G. Lemaitre’s in the Big Bang Theory. He took part in theory of the expansion of cosmos and made Lemaître coordination system. He proposed the basic theoretical properties of the cosmos, which expands as predicted by Hubble’s law. Also he determined theoretically and experimental form of the Hubble law and first proposed the value of Hubble constant. He proposed model of cosmos which called “the Hypothesis of Primordial Atom” and later called it “the Begining of the World” or “the Cosmic Egg”.
PB  - Belgrade : Astronomical Society "Rudjer Bošković"
C3  - Зборник радова конференције “Развој астрономије код Срба XI”
T1  - Допринос Жоржа Леметра теорији великог праска
T1  - The Contribution of Abbe G. Lemaitre to the Big Bang Theory
IS  - 22
SP  - 381
EP  - 394
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11236
ER  - 

@conference{
author = "Lazarov, Nenad Đ. and Nikolić, Violeta N.",
year = "2022",
abstract = "Рад се бави учешћем Жоржа Леметра у теорији великог праска. Његов допринос се огледа у теорији ширења свемира, теорији великог праска и увођењу Леметрових координата. Предложио је теоретске основе свемира који се шири што је потврдио Едвин Хабл. Имао је значајно учешће у формирању Хабловог закона и први је предложио вредност Хаблове константе. Он је такође предложио модел свемира који је назвао хипотеза исконског атома или Космичко јаје., In this paper, we represented the participation of Abbe G. Lemaitre’s in the Big Bang Theory. He took part in theory of the expansion of cosmos and made Lemaître coordination system. He proposed the basic theoretical properties of the cosmos, which expands as predicted by Hubble’s law. Also he determined theoretically and experimental form of the Hubble law and first proposed the value of Hubble constant. He proposed model of cosmos which called “the Hypothesis of Primordial Atom” and later called it “the Begining of the World” or “the Cosmic Egg”.",
publisher = "Belgrade : Astronomical Society "Rudjer Bošković"",
journal = "Зборник радова конференције “Развој астрономије код Срба XI”",
title = "Допринос Жоржа Леметра теорији великог праска, The Contribution of Abbe G. Lemaitre to the Big Bang Theory",
number = "22",
pages = "381-394",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11236"
}

Lazarov, N. Đ.,& Nikolić, V. N.. (2022). Допринос Жоржа Леметра теорији великог праска. in Зборник радова конференције “Развој астрономије код Срба XI”
Belgrade : Astronomical Society "Rudjer Bošković".(22), 381-394.
https://hdl.handle.net/21.15107/rcub_vinar_11236

Lazarov NĐ, Nikolić VN. Допринос Жоржа Леметра теорији великог праска. in Зборник радова конференције “Развој астрономије код Срба XI”. 2022;(22):381-394.
https://hdl.handle.net/21.15107/rcub_vinar_11236 .

Lazarov, Nenad Đ., Nikolić, Violeta N., "Допринос Жоржа Леметра теорији великог праска" in Зборник радова конференције “Развој астрономије код Срба XI”, no. 22 (2022):381-394,
https://hdl.handle.net/21.15107/rcub_vinar_11236 .

TY  - CONF
AU  - Nikolić, Violeta N.
AU  - Lazarov, Nenad Đ.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11237
AB  - У раду се дискутују основне информације о астероидима, до којих се дошло након њиховог скоријег открића (XIX век). Имајући у виду да је Србија у време открића првог астероида (1801) још увек била под турском влашћу (за време чије владавине се није придавала посебна пажња науци), а да развој астрономије у нашој земљи, практично, почиње 1926-е године, започињање серије окрића астероида само десет година након тог догађаја (1936), од стране српских научника, представља изванредан успех. Посебно ако узмемо у обзир да је Србија у то време била у веома тешкој геополитичкој ситуацији, јер се налазила између два светска рата. Последично, више пажње у овом раду, посвећено је српском астроному, Петру Ђурковићу, који је започео серију открића астероида, и тиме отворио ново поглавље у српској астрономији.
AB  - In this paper, we represented the participation of Abbe G. Lemaitre’s in the Big Bang Theory. He took part in theory of the expansion of cosmos and made Lemaître coordination system. He proposed the basic theoretical properties of the cosmos, which expands as predicted by Hubble’s law. Also he determined theoretically and experimental form of the Hubble law and first proposed the value of Hubble constant. He proposed model of cosmos which called “the Hypothesis of Primordial Atom” and later called it “the Begining of the World” or “the Cosmic Egg”.
PB  - Belgrade : Astronomical Society "Rudjer Bošković"
C3  - Зборник радова конференције “Развој астрономије код Срба XI”
T1  - Астероиди - небески путници
T1  - Asteroids – Celestrial Travelers
IS  - 22
SP  - 327
EP  - 341
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11237
ER  - 

@conference{
author = "Nikolić, Violeta N. and Lazarov, Nenad Đ.",
year = "2022",
abstract = "У раду се дискутују основне информације о астероидима, до којих се дошло након њиховог скоријег открића (XIX век). Имајући у виду да је Србија у време открића првог астероида (1801) још увек била под турском влашћу (за време чије владавине се није придавала посебна пажња науци), а да развој астрономије у нашој земљи, практично, почиње 1926-е године, започињање серије окрића астероида само десет година након тог догађаја (1936), од стране српских научника, представља изванредан успех. Посебно ако узмемо у обзир да је Србија у то време била у веома тешкој геополитичкој ситуацији, јер се налазила између два светска рата. Последично, више пажње у овом раду, посвећено је српском астроному, Петру Ђурковићу, који је започео серију открића астероида, и тиме отворио ново поглавље у српској астрономији., In this paper, we represented the participation of Abbe G. Lemaitre’s in the Big Bang Theory. He took part in theory of the expansion of cosmos and made Lemaître coordination system. He proposed the basic theoretical properties of the cosmos, which expands as predicted by Hubble’s law. Also he determined theoretically and experimental form of the Hubble law and first proposed the value of Hubble constant. He proposed model of cosmos which called “the Hypothesis of Primordial Atom” and later called it “the Begining of the World” or “the Cosmic Egg”.",
publisher = "Belgrade : Astronomical Society "Rudjer Bošković"",
journal = "Зборник радова конференције “Развој астрономије код Срба XI”",
title = "Астероиди - небески путници, Asteroids – Celestrial Travelers",
number = "22",
pages = "327-341",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11237"
}

Nikolić, V. N.,& Lazarov, N. Đ.. (2022). Астероиди - небески путници. in Зборник радова конференције “Развој астрономије код Срба XI”
Belgrade : Astronomical Society "Rudjer Bošković".(22), 327-341.
https://hdl.handle.net/21.15107/rcub_vinar_11237

Nikolić VN, Lazarov NĐ. Астероиди - небески путници. in Зборник радова конференције “Развој астрономије код Срба XI”. 2022;(22):327-341.
https://hdl.handle.net/21.15107/rcub_vinar_11237 .

Nikolić, Violeta N., Lazarov, Nenad Đ., "Астероиди - небески путници" in Зборник радова конференције “Развој астрономије код Срба XI”, no. 22 (2022):327-341,
https://hdl.handle.net/21.15107/rcub_vinar_11237 .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Vasić, Milica
AU  - Milikić, Jadranka
AU  - Mariano, Jose F.M.L.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9131
AB  - Abstract: The nanocomposite samples, containing copper and iron species in the silica matrix, were prepared by annealing at temperatures up to 1100°C. The samples were investigated by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and cyclic voltammetry. The results of the performed study depict to the presence of a temperature gradient, which acts on the sample during the annealing treatment in the furnace. For the first time, the influence of the temperature gradient on the formation mechanism of the samples was discussed. © 2021, Pleiades Publishing, Ltd.
T2  - Physics of the Solid State
T1  - The Influence of Thermal Treatment on the Formation Mechanism of the Cu, Fe-Containing Nanocomposite Material Synthesized by the Sol–Gel Method
VL  - 63
IS  - 2
SP  - 332
EP  - 354
DO  - 10.1134/S1063783421020207
ER  - 

@article{
author = "Nikolić, Violeta N. and Vasić, Milica and Milikić, Jadranka and Mariano, Jose F.M.L.",
year = "2021",
abstract = "Abstract: The nanocomposite samples, containing copper and iron species in the silica matrix, were prepared by annealing at temperatures up to 1100°C. The samples were investigated by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and cyclic voltammetry. The results of the performed study depict to the presence of a temperature gradient, which acts on the sample during the annealing treatment in the furnace. For the first time, the influence of the temperature gradient on the formation mechanism of the samples was discussed. © 2021, Pleiades Publishing, Ltd.",
journal = "Physics of the Solid State",
title = "The Influence of Thermal Treatment on the Formation Mechanism of the Cu, Fe-Containing Nanocomposite Material Synthesized by the Sol–Gel Method",
volume = "63",
number = "2",
pages = "332-354",
doi = "10.1134/S1063783421020207"
}

Nikolić, V. N., Vasić, M., Milikić, J.,& Mariano, J. F.M.L.. (2021). The Influence of Thermal Treatment on the Formation Mechanism of the Cu, Fe-Containing Nanocomposite Material Synthesized by the Sol–Gel Method. in Physics of the Solid State, 63(2), 332-354.
https://doi.org/10.1134/S1063783421020207

Nikolić VN, Vasić M, Milikić J, Mariano JF. The Influence of Thermal Treatment on the Formation Mechanism of the Cu, Fe-Containing Nanocomposite Material Synthesized by the Sol–Gel Method. in Physics of the Solid State. 2021;63(2):332-354.
doi:10.1134/S1063783421020207 .

Nikolić, Violeta N., Vasić, Milica, Milikić, Jadranka, Mariano, Jose F.M.L., "The Influence of Thermal Treatment on the Formation Mechanism of the Cu, Fe-Containing Nanocomposite Material Synthesized by the Sol–Gel Method" in Physics of the Solid State, 63, no. 2 (2021):332-354,
https://doi.org/10.1134/S1063783421020207 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Tadić, Marin
AU  - Jovanović, Sonja
AU  - Spasojević, Vojislav
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0272884219314166
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8220
AB  - We performed structural and magnetic investigation of Fe3O4/OA nanoparticles prepared by solvothermal method. Based on XRD, TEM and FTIR examination, investigated sample contained monodisperse, 5 nm-sized spherical magnetite nanoparticles coated with oleic acid. Magnetic measurement of the hysteretic curves at 5 K in zero-field cooled (ZFC) and field-cooled (FC) regime confirmed presence of exchange bias effect. ZFC/FC measurements were performed in applied magnetic fields: 10 Oe, 100 Oe, 200 Oe, 500 Oe and 1000 Oe. Zero-field cooled magnetization curves recorded in 10 Oe and 100 Oe exhibited behavior characteristic for low coercivity Nanomaterials. Same sample exposed to the ZFC/FC measurement protocol in 200 Oe, 500 Oe and 1000 Oe showed increase in ZFC magnetization in the certain temperature range. The observed feature is attributed to the local changes in the magnetite electronic structure, occurred through the spin reorientation process. © 2019 Elsevier Ltd and Techna Group S.r.l.
T2  - Ceramics International
T1  - Tracking of the electronic re-ordering in Fe3O4/OA nanoparticles using magnetometry
VL  - 45
IS  - 14
SP  - 17429
EP  - 17437
DO  - 10.1016/j.ceramint.2019.05.303
ER  - 

@article{
author = "Nikolić, Violeta N. and Tadić, Marin and Jovanović, Sonja and Spasojević, Vojislav",
year = "2019",
abstract = "We performed structural and magnetic investigation of Fe3O4/OA nanoparticles prepared by solvothermal method. Based on XRD, TEM and FTIR examination, investigated sample contained monodisperse, 5 nm-sized spherical magnetite nanoparticles coated with oleic acid. Magnetic measurement of the hysteretic curves at 5 K in zero-field cooled (ZFC) and field-cooled (FC) regime confirmed presence of exchange bias effect. ZFC/FC measurements were performed in applied magnetic fields: 10 Oe, 100 Oe, 200 Oe, 500 Oe and 1000 Oe. Zero-field cooled magnetization curves recorded in 10 Oe and 100 Oe exhibited behavior characteristic for low coercivity Nanomaterials. Same sample exposed to the ZFC/FC measurement protocol in 200 Oe, 500 Oe and 1000 Oe showed increase in ZFC magnetization in the certain temperature range. The observed feature is attributed to the local changes in the magnetite electronic structure, occurred through the spin reorientation process. © 2019 Elsevier Ltd and Techna Group S.r.l.",
journal = "Ceramics International",
title = "Tracking of the electronic re-ordering in Fe3O4/OA nanoparticles using magnetometry",
volume = "45",
number = "14",
pages = "17429-17437",
doi = "10.1016/j.ceramint.2019.05.303"
}

Nikolić, V. N., Tadić, M., Jovanović, S.,& Spasojević, V.. (2019). Tracking of the electronic re-ordering in Fe3O4/OA nanoparticles using magnetometry. in Ceramics International, 45(14), 17429-17437.
https://doi.org/10.1016/j.ceramint.2019.05.303

Nikolić VN, Tadić M, Jovanović S, Spasojević V. Tracking of the electronic re-ordering in Fe3O4/OA nanoparticles using magnetometry. in Ceramics International. 2019;45(14):17429-17437.
doi:10.1016/j.ceramint.2019.05.303 .

Nikolić, Violeta N., Tadić, Marin, Jovanović, Sonja, Spasojević, Vojislav, "Tracking of the electronic re-ordering in Fe3O4/OA nanoparticles using magnetometry" in Ceramics International, 45, no. 14 (2019):17429-17437,
https://doi.org/10.1016/j.ceramint.2019.05.303 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Gilić, Martina D.
AU  - Spasojević, Vojislav
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10287
AB  - Nanocomposite material containing NiO nanoparticles decorated on WO3 nanowires could be used for monitoring levels of H2S gas. The effectiveness of this material is mostly determined by NiO properties. The performed study presents the first stage in the preparation of modified NiO/WO3 nanocomposite material. In this article, NiO nanoparticles are prepared by a simple, low-cost method.The behavior of nano-sized NiO particles is probed by X-ray diffraction, Fourier transform Infrared Spectroscopy, Raman spectroscopy, and hysteretic measurement.
T2  - Vojnotehnički glasnik
T1  - Characterization of NiO nanoparticles prepared using gelatin and a low-cost synthesis
T1  - Karakterizacija NiO nanočestica pripremljenih pomoću želatina tokom postupka 'low-cost' sinteze
VL  - 67
IS  - 1
SP  - 36
EP  - 52
DO  - 10.5937/vojtehg67-18535
ER  - 

@article{
author = "Nikolić, Violeta N. and Gilić, Martina D. and Spasojević, Vojislav",
year = "2019",
abstract = "Nanocomposite material containing NiO nanoparticles decorated on WO3 nanowires could be used for monitoring levels of H2S gas. The effectiveness of this material is mostly determined by NiO properties. The performed study presents the first stage in the preparation of modified NiO/WO3 nanocomposite material. In this article, NiO nanoparticles are prepared by a simple, low-cost method.The behavior of nano-sized NiO particles is probed by X-ray diffraction, Fourier transform Infrared Spectroscopy, Raman spectroscopy, and hysteretic measurement.",
journal = "Vojnotehnički glasnik",
title = "Characterization of NiO nanoparticles prepared using gelatin and a low-cost synthesis, Karakterizacija NiO nanočestica pripremljenih pomoću želatina tokom postupka 'low-cost' sinteze",
volume = "67",
number = "1",
pages = "36-52",
doi = "10.5937/vojtehg67-18535"
}

Nikolić, V. N., Gilić, M. D.,& Spasojević, V.. (2019). Characterization of NiO nanoparticles prepared using gelatin and a low-cost synthesis. in Vojnotehnički glasnik, 67(1), 36-52.
https://doi.org/10.5937/vojtehg67-18535

Nikolić VN, Gilić MD, Spasojević V. Characterization of NiO nanoparticles prepared using gelatin and a low-cost synthesis. in Vojnotehnički glasnik. 2019;67(1):36-52.
doi:10.5937/vojtehg67-18535 .

Nikolić, Violeta N., Gilić, Martina D., Spasojević, Vojislav, "Characterization of NiO nanoparticles prepared using gelatin and a low-cost synthesis" in Vojnotehnički glasnik, 67, no. 1 (2019):36-52,
https://doi.org/10.5937/vojtehg67-18535 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Milić, Mirjana M.
AU  - Zdravković, Jelena D.
AU  - Spasojević, Vojislav
PY  - 2019
UR  - http://link.springer.com/10.1134/S0036024419030130
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8213
AB  - Abstract: Origin of the intrinsic coercivity field variations observed by hysteretic measurements established by Nikolic et al. was investigated in detail by ZFC/FC measurements. In this study, magnetic behavior of the samples is further examined by calculation of the ZFC Mn(T) and Mn(H) first derivatives. Performed study showed that the main contribution to the measured coercivity comes from the ε-Fe2O3 particles, characterized by Hci = 24 kOe, although both samples posses SPM ε-Fe2O3 fraction. As a result, Hci values of the samples are differed dependent on the quantity of the SPM ε-Fe2O3 particles in the sample. Mechanism of the intrisic coercivity field variations is discussed. © 2019, Pleiades Publishing, Ltd.
T2  - Russian Journal of Physical Chemistry A
T1  - Origin of the Intrinsic Coercivity Field Variations and Magnetic Study of ε-Fe2O3
VL  - 93
IS  - 3
SP  - 588
EP  - 593
DO  - 10.1134/S0036024419030130
ER  - 

@article{
author = "Nikolić, Violeta N. and Milić, Mirjana M. and Zdravković, Jelena D. and Spasojević, Vojislav",
year = "2019",
abstract = "Abstract: Origin of the intrinsic coercivity field variations observed by hysteretic measurements established by Nikolic et al. was investigated in detail by ZFC/FC measurements. In this study, magnetic behavior of the samples is further examined by calculation of the ZFC Mn(T) and Mn(H) first derivatives. Performed study showed that the main contribution to the measured coercivity comes from the ε-Fe2O3 particles, characterized by Hci = 24 kOe, although both samples posses SPM ε-Fe2O3 fraction. As a result, Hci values of the samples are differed dependent on the quantity of the SPM ε-Fe2O3 particles in the sample. Mechanism of the intrisic coercivity field variations is discussed. © 2019, Pleiades Publishing, Ltd.",
journal = "Russian Journal of Physical Chemistry A",
title = "Origin of the Intrinsic Coercivity Field Variations and Magnetic Study of ε-Fe2O3",
volume = "93",
number = "3",
pages = "588-593",
doi = "10.1134/S0036024419030130"
}

Nikolić, V. N., Milić, M. M., Zdravković, J. D.,& Spasojević, V.. (2019). Origin of the Intrinsic Coercivity Field Variations and Magnetic Study of ε-Fe2O3. in Russian Journal of Physical Chemistry A, 93(3), 588-593.
https://doi.org/10.1134/S0036024419030130

Nikolić VN, Milić MM, Zdravković JD, Spasojević V. Origin of the Intrinsic Coercivity Field Variations and Magnetic Study of ε-Fe2O3. in Russian Journal of Physical Chemistry A. 2019;93(3):588-593.
doi:10.1134/S0036024419030130 .

Nikolić, Violeta N., Milić, Mirjana M., Zdravković, Jelena D., Spasojević, Vojislav, "Origin of the Intrinsic Coercivity Field Variations and Magnetic Study of ε-Fe2O3" in Russian Journal of Physical Chemistry A, 93, no. 3 (2019):588-593,
https://doi.org/10.1134/S0036024419030130 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Milić, Mirjana M.
AU  - Zdravković, Jelena D.
AU  - Spasojević, Vojislav
PY  - 2019
UR  - http://link.springer.com/10.1134/S0036024419020316
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8214
AB  - Abstract: ε-Fe2O3 phase is recognized as an attractive material, in both technological and scientific point of view, since it can achieve very high room-temperature coercivity (10–20 kOe). In this paper, multi-phase samples Fe2O3/SiO2 with slightly different Fe/Si molar ratio were produced by sol–gel synthesis route. The obtained samples were characterized by various experimental techniques including XRD, TA, FTIR, and SQUID (DC and AC magnetic measurements). It was found that both samples consisted of α-Fe2O3 and ε‑Fe2O3 phases embedded in the silica matrix, and showed very similar structural and magnetic properties, except that displayed significantly different room-temperature intrinsic coercivity field values: HciS1 = 14.3 kOe and HciS2 = 7.5 kOe. We have discussed possible origin of thus high intrinsic coercivity field variation. © 2019, Pleiades Publishing, Ltd.
T2  - Russian Journal of Physical Chemistry A
T1  - Origin of the Intrinsic Coercivity Field Variations of ε-Fe2O3
VL  - 93
IS  - 2
SP  - 377
EP  - 383
DO  - 10.1134/S0036024419020316
ER  - 

@article{
author = "Nikolić, Violeta N. and Milić, Mirjana M. and Zdravković, Jelena D. and Spasojević, Vojislav",
year = "2019",
abstract = "Abstract: ε-Fe2O3 phase is recognized as an attractive material, in both technological and scientific point of view, since it can achieve very high room-temperature coercivity (10–20 kOe). In this paper, multi-phase samples Fe2O3/SiO2 with slightly different Fe/Si molar ratio were produced by sol–gel synthesis route. The obtained samples were characterized by various experimental techniques including XRD, TA, FTIR, and SQUID (DC and AC magnetic measurements). It was found that both samples consisted of α-Fe2O3 and ε‑Fe2O3 phases embedded in the silica matrix, and showed very similar structural and magnetic properties, except that displayed significantly different room-temperature intrinsic coercivity field values: HciS1 = 14.3 kOe and HciS2 = 7.5 kOe. We have discussed possible origin of thus high intrinsic coercivity field variation. © 2019, Pleiades Publishing, Ltd.",
journal = "Russian Journal of Physical Chemistry A",
title = "Origin of the Intrinsic Coercivity Field Variations of ε-Fe2O3",
volume = "93",
number = "2",
pages = "377-383",
doi = "10.1134/S0036024419020316"
}

Nikolić, V. N., Milić, M. M., Zdravković, J. D.,& Spasojević, V.. (2019). Origin of the Intrinsic Coercivity Field Variations of ε-Fe2O3. in Russian Journal of Physical Chemistry A, 93(2), 377-383.
https://doi.org/10.1134/S0036024419020316

Nikolić VN, Milić MM, Zdravković JD, Spasojević V. Origin of the Intrinsic Coercivity Field Variations of ε-Fe2O3. in Russian Journal of Physical Chemistry A. 2019;93(2):377-383.
doi:10.1134/S0036024419020316 .

Nikolić, Violeta N., Milić, Mirjana M., Zdravković, Jelena D., Spasojević, Vojislav, "Origin of the Intrinsic Coercivity Field Variations of ε-Fe2O3" in Russian Journal of Physical Chemistry A, 93, no. 2 (2019):377-383,
https://doi.org/10.1134/S0036024419020316 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Vasić, Milica M.
AU  - Kisić, Danilo
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S002245961930177X
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8160
AB  - Two samples containing 2-line ferrihydrite and copper oxide were synthesized by coprecipitation method, via variation of Fe3+ and Cu2+ precursors milimolar ratio (3:1 and 3:3.1), while the other synthesis parameters were kept constant. Annealing treatment at 1100 °C resulted in the formation of c-CuFe2O4-CuO-α-Fe2O3 and c-CuFe2O4-CuO nanocomposites, respectively. A comparison of properties of the prepared samples was performed by XRD, FTIR and EPR measurements. Formation mechanism of the nanocomposites is discussed with a reference to the influence of Jahn-Teller effect in CuO phase on the final CuFe2O4 structure. For the first time, it is shown that the amount of Fe3+ precursor is of key importance for the size of CuFe2O4 nanoparticles, and enables preparation of c-CuFe2O4 nanoparticles of the same crystallite size (46 nm) in different nanocomposite materials. © 2019 Elsevier Inc.
T2  - Journal of Solid State Chemistry
T1  - Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations
VL  - 275
SP  - 187
EP  - 196
DO  - 10.1016/j.jssc.2019.04.007
ER  - 

@article{
author = "Nikolić, Violeta N. and Vasić, Milica M. and Kisić, Danilo",
year = "2019",
abstract = "Two samples containing 2-line ferrihydrite and copper oxide were synthesized by coprecipitation method, via variation of Fe3+ and Cu2+ precursors milimolar ratio (3:1 and 3:3.1), while the other synthesis parameters were kept constant. Annealing treatment at 1100 °C resulted in the formation of c-CuFe2O4-CuO-α-Fe2O3 and c-CuFe2O4-CuO nanocomposites, respectively. A comparison of properties of the prepared samples was performed by XRD, FTIR and EPR measurements. Formation mechanism of the nanocomposites is discussed with a reference to the influence of Jahn-Teller effect in CuO phase on the final CuFe2O4 structure. For the first time, it is shown that the amount of Fe3+ precursor is of key importance for the size of CuFe2O4 nanoparticles, and enables preparation of c-CuFe2O4 nanoparticles of the same crystallite size (46 nm) in different nanocomposite materials. © 2019 Elsevier Inc.",
journal = "Journal of Solid State Chemistry",
title = "Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations",
volume = "275",
pages = "187-196",
doi = "10.1016/j.jssc.2019.04.007"
}

Nikolić, V. N., Vasić, M. M.,& Kisić, D.. (2019). Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations. in Journal of Solid State Chemistry, 275, 187-196.
https://doi.org/10.1016/j.jssc.2019.04.007

Nikolić VN, Vasić MM, Kisić D. Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations. in Journal of Solid State Chemistry. 2019;275:187-196.
doi:10.1016/j.jssc.2019.04.007 .

Nikolić, Violeta N., Vasić, Milica M., Kisić, Danilo, "Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations" in Journal of Solid State Chemistry, 275 (2019):187-196,
https://doi.org/10.1016/j.jssc.2019.04.007 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Vasić, Milica M.
AU  - Milić, Mirjana M.
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7876
AB  - Samples containing CuFe2O4 and CuO nanoparticles were synthesized by coprecipitation method and subjected to thermal treatment at 300 °C, 500 °C, 700 °C, 900 °C and 1100 °C. Depending on the synthesis conditions, high-temperature treatment of the prepared samples brought to the formation of CuFe2O4 with a tetragonal or cubic structure, which was confirmed by X-ray diffraction analysis. The influence of formation mechanism onto the crystallite sizes of nanoparticles and structural transformation of CuFe2O4 is discussed. For the first time it was shown that variations of the initial amount of Fe3+ and Cu2+ ions precursors resulted in the formation of low- and high-temperature CuFe2O4 phase at the same annealing temperature, 1100 °C. © 2018
T2  - Ceramics International
T1  - Observation of low- and high-temperature CuFe2O4 phase at 1100 °C: The influence of Fe3+ ions on CuFe2O4 structural transformation
VL  - 44
IS  - 17
SP  - 21145
EP  - 21152
DO  - 10.1016/j.ceramint.2018.08.157
ER  - 

@article{
author = "Nikolić, Violeta N. and Vasić, Milica M. and Milić, Mirjana M.",
year = "2018",
abstract = "Samples containing CuFe2O4 and CuO nanoparticles were synthesized by coprecipitation method and subjected to thermal treatment at 300 °C, 500 °C, 700 °C, 900 °C and 1100 °C. Depending on the synthesis conditions, high-temperature treatment of the prepared samples brought to the formation of CuFe2O4 with a tetragonal or cubic structure, which was confirmed by X-ray diffraction analysis. The influence of formation mechanism onto the crystallite sizes of nanoparticles and structural transformation of CuFe2O4 is discussed. For the first time it was shown that variations of the initial amount of Fe3+ and Cu2+ ions precursors resulted in the formation of low- and high-temperature CuFe2O4 phase at the same annealing temperature, 1100 °C. © 2018",
journal = "Ceramics International",
title = "Observation of low- and high-temperature CuFe2O4 phase at 1100 °C: The influence of Fe3+ ions on CuFe2O4 structural transformation",
volume = "44",
number = "17",
pages = "21145-21152",
doi = "10.1016/j.ceramint.2018.08.157"
}

Nikolić, V. N., Vasić, M. M.,& Milić, M. M.. (2018). Observation of low- and high-temperature CuFe2O4 phase at 1100 °C: The influence of Fe3+ ions on CuFe2O4 structural transformation. in Ceramics International, 44(17), 21145-21152.
https://doi.org/10.1016/j.ceramint.2018.08.157

Nikolić VN, Vasić MM, Milić MM. Observation of low- and high-temperature CuFe2O4 phase at 1100 °C: The influence of Fe3+ ions on CuFe2O4 structural transformation. in Ceramics International. 2018;44(17):21145-21152.
doi:10.1016/j.ceramint.2018.08.157 .

Nikolić, Violeta N., Vasić, Milica M., Milić, Mirjana M., "Observation of low- and high-temperature CuFe2O4 phase at 1100 °C: The influence of Fe3+ ions on CuFe2O4 structural transformation" in Ceramics International, 44, no. 17 (2018):21145-21152,
https://doi.org/10.1016/j.ceramint.2018.08.157 . .

TY  - CONF
AU  - Nikolić, Violeta N.
AU  - Tadić, Marin
AU  - Mraković, Ana Đ.
AU  - Spasojević, Vojislav
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7850
AB  - Nano iron oxides have been intensively investigated due to their various potential biomedical applications. ε-Fe2O3 phase exerted internal coercivity value up to ~20 kOe, high Curie temperature (Tc= 510 K), and magnetoelectric character. Accordingly, epsilon phase is recognized as a suitable material for medical spintronic biosensors production, that present important part for the lab-on-a-chip systems. Noteworthy, ε-Fe2O3 phase exerts peculiar magnetic behavior. To get better insight into the magnetism of this material, ε-Fe2O3/SiO2 sample was prepared by the combination of the sol-gel synthesis and microemulsion method (Tann=1050 °C, tann= 4h). Afterwards, the sample was exposed to post-annealing treatment at 100 °C and 200 °C. Synthesized material was preliminary examined by XRD and SQUID techniques. Coercivity changes, induced by the post-annealing temperature oscillations, were monitored by hysteretic measurements. Sample annealed at 1050 °C for 4h, showed coercivity ~20 kOe. The same sample performed to the post-annealing treatment at 100 °C, exerted significantly decreased coercivity (~1600 Oe). Further rise of the post-annealing temperature (200 °C) resulted in the increased coercivity ~15 kOe. Obtained study showed that there is insufficient knowledge concerning the ε-Fe2O3 coercivity changes of the polymorph. The more detailed investigation will be conducted, in order to advance the control of the epsilon phase magnetic properties. © 2018 TANGER Ltd. All Rights Reserved.
C3  - NANOCON 2017 - Conference Proceedings, 9th International Conference on Nanomaterials - Research and Application
T1  - Unusual temperature dependence of coercivity in ε-Fe2O3 phase
VL  - 2017-October
SP  - 27
EP  - 32
UR  - https://hdl.handle.net/21.15107/rcub_vinar_7850
ER  - 

@conference{
author = "Nikolić, Violeta N. and Tadić, Marin and Mraković, Ana Đ. and Spasojević, Vojislav",
year = "2018",
abstract = "Nano iron oxides have been intensively investigated due to their various potential biomedical applications. ε-Fe2O3 phase exerted internal coercivity value up to ~20 kOe, high Curie temperature (Tc= 510 K), and magnetoelectric character. Accordingly, epsilon phase is recognized as a suitable material for medical spintronic biosensors production, that present important part for the lab-on-a-chip systems. Noteworthy, ε-Fe2O3 phase exerts peculiar magnetic behavior. To get better insight into the magnetism of this material, ε-Fe2O3/SiO2 sample was prepared by the combination of the sol-gel synthesis and microemulsion method (Tann=1050 °C, tann= 4h). Afterwards, the sample was exposed to post-annealing treatment at 100 °C and 200 °C. Synthesized material was preliminary examined by XRD and SQUID techniques. Coercivity changes, induced by the post-annealing temperature oscillations, were monitored by hysteretic measurements. Sample annealed at 1050 °C for 4h, showed coercivity ~20 kOe. The same sample performed to the post-annealing treatment at 100 °C, exerted significantly decreased coercivity (~1600 Oe). Further rise of the post-annealing temperature (200 °C) resulted in the increased coercivity ~15 kOe. Obtained study showed that there is insufficient knowledge concerning the ε-Fe2O3 coercivity changes of the polymorph. The more detailed investigation will be conducted, in order to advance the control of the epsilon phase magnetic properties. © 2018 TANGER Ltd. All Rights Reserved.",
journal = "NANOCON 2017 - Conference Proceedings, 9th International Conference on Nanomaterials - Research and Application",
title = "Unusual temperature dependence of coercivity in ε-Fe2O3 phase",
volume = "2017-October",
pages = "27-32",
url = "https://hdl.handle.net/21.15107/rcub_vinar_7850"
}

Nikolić, V. N., Tadić, M., Mraković, A. Đ.,& Spasojević, V.. (2018). Unusual temperature dependence of coercivity in ε-Fe2O3 phase. in NANOCON 2017 - Conference Proceedings, 9th International Conference on Nanomaterials - Research and Application, 2017-October, 27-32.
https://hdl.handle.net/21.15107/rcub_vinar_7850

Nikolić VN, Tadić M, Mraković AĐ, Spasojević V. Unusual temperature dependence of coercivity in ε-Fe2O3 phase. in NANOCON 2017 - Conference Proceedings, 9th International Conference on Nanomaterials - Research and Application. 2018;2017-October:27-32.
https://hdl.handle.net/21.15107/rcub_vinar_7850 .

Nikolić, Violeta N., Tadić, Marin, Mraković, Ana Đ., Spasojević, Vojislav, "Unusual temperature dependence of coercivity in ε-Fe2O3 phase" in NANOCON 2017 - Conference Proceedings, 9th International Conference on Nanomaterials - Research and Application, 2017-October (2018):27-32,
https://hdl.handle.net/21.15107/rcub_vinar_7850 .

TY  - JOUR
AU  - Šaponjić, Aleksandra
AU  - Šaponjić, Đorđe
AU  - Nikolić, Violeta N.
AU  - Milošević, Maja
AU  - Marinović-Cincović, Milena
AU  - Gyoshev, Stanislav
AU  - Vuković, Marina
AU  - Kokunešoski, Maja
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1644
AB  - Amorphous iron (III) oxide was obtained from clay, using ammonium hydroxide as a precipitating agent. Influence of freeze drying under vacuum, as a drying method, on particle size, chemical composition, and crystallinity of obtained iron (III) oxide powder was investigated. After freeze drying, precipitate was annealed in air at 500 C-o and 900 oC. X-ray diffraction, particle size analysis, scanning electron microscopy, energy dispersive spectrometry, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis were used to characterize obtained iron (III) oxide powder. All of three powders obtained by freeze drying and annealing, have low crystallinity and particles with irregular layered shape. Narrow particle size distribution was given by an average diameter value of around 50 mu m for all observed powders. Iron-bearing materials like a-Fe2O3 and gamma-Fe2O3 are obtained. Differential thermal analysis curve of obtained samples showed endothermic reaction at 620 oC which could be ascribed to phase transition from cubic form gamma- - GT alpha- Fe2O3. Thermal transformations of iron (III) oxide, obtained from clay as a natural source, is suitable to explore in the framework of materials chemistry, and opens the possibility to synthesize materials based on Fe2O3 with specific magnetic behavior.
T2  - Science of Sintering
T1  - Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3
VL  - 49
IS  - 2
SP  - 197
EP  - 205
DO  - 10.2298/SOS1702197S
ER  - 

@article{
author = "Šaponjić, Aleksandra and Šaponjić, Đorđe and Nikolić, Violeta N. and Milošević, Maja and Marinović-Cincović, Milena and Gyoshev, Stanislav and Vuković, Marina and Kokunešoski, Maja",
year = "2017",
abstract = "Amorphous iron (III) oxide was obtained from clay, using ammonium hydroxide as a precipitating agent. Influence of freeze drying under vacuum, as a drying method, on particle size, chemical composition, and crystallinity of obtained iron (III) oxide powder was investigated. After freeze drying, precipitate was annealed in air at 500 C-o and 900 oC. X-ray diffraction, particle size analysis, scanning electron microscopy, energy dispersive spectrometry, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis were used to characterize obtained iron (III) oxide powder. All of three powders obtained by freeze drying and annealing, have low crystallinity and particles with irregular layered shape. Narrow particle size distribution was given by an average diameter value of around 50 mu m for all observed powders. Iron-bearing materials like a-Fe2O3 and gamma-Fe2O3 are obtained. Differential thermal analysis curve of obtained samples showed endothermic reaction at 620 oC which could be ascribed to phase transition from cubic form gamma- - GT alpha- Fe2O3. Thermal transformations of iron (III) oxide, obtained from clay as a natural source, is suitable to explore in the framework of materials chemistry, and opens the possibility to synthesize materials based on Fe2O3 with specific magnetic behavior.",
journal = "Science of Sintering",
title = "Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3",
volume = "49",
number = "2",
pages = "197-205",
doi = "10.2298/SOS1702197S"
}

Šaponjić, A., Šaponjić, Đ., Nikolić, V. N., Milošević, M., Marinović-Cincović, M., Gyoshev, S., Vuković, M.,& Kokunešoski, M.. (2017). Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3. in Science of Sintering, 49(2), 197-205.
https://doi.org/10.2298/SOS1702197S

Šaponjić A, Šaponjić Đ, Nikolić VN, Milošević M, Marinović-Cincović M, Gyoshev S, Vuković M, Kokunešoski M. Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3. in Science of Sintering. 2017;49(2):197-205.
doi:10.2298/SOS1702197S .

Šaponjić, Aleksandra, Šaponjić, Đorđe, Nikolić, Violeta N., Milošević, Maja, Marinović-Cincović, Milena, Gyoshev, Stanislav, Vuković, Marina, Kokunešoski, Maja, "Iron (III) Oxide Fabrication From Natural Clay With Reference to Phase Transformation gamma- - GT alpha- Fe2O3" in Science of Sintering, 49, no. 2 (2017):197-205,
https://doi.org/10.2298/SOS1702197S . .

TY  - JOUR
AU  - Milić, Mirjana M.
AU  - Nikolić, Violeta N.
AU  - Jovanović, Sonja
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1735
AB  - In this work, sol gel method was used to prepare FexOy/Gd2O3/SiO2 composite system starting from two different iron precursors: iron nitrate and iron oxide xerogel. The obtained samples were subjected to heat treatment at different temperatures under atmospheric conditions. Thermal evolution of the prepared samples has been systematically investigated by using X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR). Samples calcined at 1030 degrees C were also characterized by transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) experimental techniques. Effect of thermal treatment on phase formation in the prepared composite system has been discussed. It was found that iron nitrate based sample developed only alpha-Fe2O3 structural phase, while the sample based on the iron oxide xerogel developed alpha-Fe2O3 and gamma-Fe2O3 phases, with both of them remaining stable up to temperatures as high as 1030 degrees C. Gadolinium precursor crystallized directly in low-temperature triclinic B-type gadolinium disilicate Gd2Si2O7 (Gd2O3 center dot 2SiO(2)) phase at 900 degrees C, without formation of intermediate monosilicate phase. No other crystalline phases related to gadolinium were observed.
T2  - Ceramics International
T1  - Synthesis and characterization of nanocrystalline FexOy/Gd2O3/SiO2 composite powder
VL  - 43
IS  - 16
SP  - 14044
EP  - 14049
DO  - 10.1016/j.ceramint.2017.07.138
ER  - 

@article{
author = "Milić, Mirjana M. and Nikolić, Violeta N. and Jovanović, Sonja",
year = "2017",
abstract = "In this work, sol gel method was used to prepare FexOy/Gd2O3/SiO2 composite system starting from two different iron precursors: iron nitrate and iron oxide xerogel. The obtained samples were subjected to heat treatment at different temperatures under atmospheric conditions. Thermal evolution of the prepared samples has been systematically investigated by using X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR). Samples calcined at 1030 degrees C were also characterized by transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) experimental techniques. Effect of thermal treatment on phase formation in the prepared composite system has been discussed. It was found that iron nitrate based sample developed only alpha-Fe2O3 structural phase, while the sample based on the iron oxide xerogel developed alpha-Fe2O3 and gamma-Fe2O3 phases, with both of them remaining stable up to temperatures as high as 1030 degrees C. Gadolinium precursor crystallized directly in low-temperature triclinic B-type gadolinium disilicate Gd2Si2O7 (Gd2O3 center dot 2SiO(2)) phase at 900 degrees C, without formation of intermediate monosilicate phase. No other crystalline phases related to gadolinium were observed.",
journal = "Ceramics International",
title = "Synthesis and characterization of nanocrystalline FexOy/Gd2O3/SiO2 composite powder",
volume = "43",
number = "16",
pages = "14044-14049",
doi = "10.1016/j.ceramint.2017.07.138"
}

Milić, M. M., Nikolić, V. N.,& Jovanović, S.. (2017). Synthesis and characterization of nanocrystalline FexOy/Gd2O3/SiO2 composite powder. in Ceramics International, 43(16), 14044-14049.
https://doi.org/10.1016/j.ceramint.2017.07.138

Milić MM, Nikolić VN, Jovanović S. Synthesis and characterization of nanocrystalline FexOy/Gd2O3/SiO2 composite powder. in Ceramics International. 2017;43(16):14044-14049.
doi:10.1016/j.ceramint.2017.07.138 .

Milić, Mirjana M., Nikolić, Violeta N., Jovanović, Sonja, "Synthesis and characterization of nanocrystalline FexOy/Gd2O3/SiO2 composite powder" in Ceramics International, 43, no. 16 (2017):14044-14049,
https://doi.org/10.1016/j.ceramint.2017.07.138 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Milić, Mirjana
AU  - Jovanović, Sonja
AU  - Girman, Vladimir
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10288
AB  - Monodisperse samples of magnetite nanoparticles in the size range of 5-13nm, were prepared by solvothermal synthesis and coprecipitation method. Obtained nanoparticles were characterized by different measurement techniques: X-ray diffraction analysis, transmission electron microscopy, selected area electron diffraction measurement, and Fourier transform infra-red spectroscopy. Measurements confirmed that the utilized synthesis methods are able to produce size and shape-controlled nanoparticles of a high-quality, that is of the technological importance. The results of the performed study represent the first stage in preparation of the Fe3O4 nanoparticles as an additive to concrete, which will be used for the construction of the special military facilities where it is necessary to provide a protection against γ-ray radiation.
T2  - Scientific Technical Review
T1  - Fe3O4 nanoparticles as additives for gamma-ray shielding: Structural and surface characterization
VL  - 67
IS  - 2
SP  - 20
EP  - 26
DO  - 10.5937/str1702020N
ER  - 

@article{
author = "Nikolić, Violeta N. and Milić, Mirjana and Jovanović, Sonja and Girman, Vladimir",
year = "2017",
abstract = "Monodisperse samples of magnetite nanoparticles in the size range of 5-13nm, were prepared by solvothermal synthesis and coprecipitation method. Obtained nanoparticles were characterized by different measurement techniques: X-ray diffraction analysis, transmission electron microscopy, selected area electron diffraction measurement, and Fourier transform infra-red spectroscopy. Measurements confirmed that the utilized synthesis methods are able to produce size and shape-controlled nanoparticles of a high-quality, that is of the technological importance. The results of the performed study represent the first stage in preparation of the Fe3O4 nanoparticles as an additive to concrete, which will be used for the construction of the special military facilities where it is necessary to provide a protection against γ-ray radiation.",
journal = "Scientific Technical Review",
title = "Fe3O4 nanoparticles as additives for gamma-ray shielding: Structural and surface characterization",
volume = "67",
number = "2",
pages = "20-26",
doi = "10.5937/str1702020N"
}

Nikolić, V. N., Milić, M., Jovanović, S.,& Girman, V.. (2017). Fe3O4 nanoparticles as additives for gamma-ray shielding: Structural and surface characterization. in Scientific Technical Review, 67(2), 20-26.
https://doi.org/10.5937/str1702020N

Nikolić VN, Milić M, Jovanović S, Girman V. Fe3O4 nanoparticles as additives for gamma-ray shielding: Structural and surface characterization. in Scientific Technical Review. 2017;67(2):20-26.
doi:10.5937/str1702020N .

Nikolić, Violeta N., Milić, Mirjana, Jovanović, Sonja, Girman, Vladimir, "Fe3O4 nanoparticles as additives for gamma-ray shielding: Structural and surface characterization" in Scientific Technical Review, 67, no. 2 (2017):20-26,
https://doi.org/10.5937/str1702020N . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Spasojević, Vojislav
AU  - Panjan, Matjaž
AU  - Kopanja, Lazar
AU  - Mraković, Ana Đ.
AU  - Tadić, Marin
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1559
AB  - Several Fe2O3/SiO2 nanostructures were synthesized by the combination of the microemulsion and a sol-gel methods. Based on X-ray powder diffraction (XRD) and magnetic measurements (giant coercivity similar to 2.13 T) we identified epsilon-Fe2O3 (hard magnet) as the dominant crystalline phase. TEM analysis showed a wide size distribution of iron oxide nanoparticles (from 4 to 50 nm) with various morphologies (spherical, ellipsoidal and rod-like). We quantitatively described (computational analysis, MATLAB code) morphological properties of nanoparticles using the ellipticity of the shapes. The as-synthesized hard magnetic material was subjected to a post-annealing treatment at different temperatures (200, 500, 750, 1000 and 1100 degrees C) in order to investigate stability, formation and transformation of the epsilon-Fe2O3 polymorph. We found decreasing coercivity in the thermally treated samples up to the temperature of 750 degrees C (H-c=1245 Oe), followed by an observation of a surprising jump in coercivity H-c similar to 1.5 T after post-annealing at 1000 degrees C. We conclude that the re-formation of the epsilon-Fe2O3 structure during post-annealing at 1000 degrees C is the origin of the observed phenomena. The phase transformation epsilon-Fe2O3 - GT alpha-Fe2O3 and crystallization of amorphous silica in quartz and cristobalite were observed in the sample treated at 1100 degrees C.
T2  - Ceramics International
T1  - Re-formation of metastable epsilon-Fe2O3 in post-annealing of Fe2O3/SiO2 nanostructure: Synthesis, computational particle shape analysis in micrographs and magnetic properties
VL  - 43
IS  - 10
SP  - 7497
EP  - 7507
DO  - 10.1016/j.ceramint.2017.03.030
ER  - 

@article{
author = "Nikolić, Violeta N. and Spasojević, Vojislav and Panjan, Matjaž and Kopanja, Lazar and Mraković, Ana Đ. and Tadić, Marin",
year = "2017",
abstract = "Several Fe2O3/SiO2 nanostructures were synthesized by the combination of the microemulsion and a sol-gel methods. Based on X-ray powder diffraction (XRD) and magnetic measurements (giant coercivity similar to 2.13 T) we identified epsilon-Fe2O3 (hard magnet) as the dominant crystalline phase. TEM analysis showed a wide size distribution of iron oxide nanoparticles (from 4 to 50 nm) with various morphologies (spherical, ellipsoidal and rod-like). We quantitatively described (computational analysis, MATLAB code) morphological properties of nanoparticles using the ellipticity of the shapes. The as-synthesized hard magnetic material was subjected to a post-annealing treatment at different temperatures (200, 500, 750, 1000 and 1100 degrees C) in order to investigate stability, formation and transformation of the epsilon-Fe2O3 polymorph. We found decreasing coercivity in the thermally treated samples up to the temperature of 750 degrees C (H-c=1245 Oe), followed by an observation of a surprising jump in coercivity H-c similar to 1.5 T after post-annealing at 1000 degrees C. We conclude that the re-formation of the epsilon-Fe2O3 structure during post-annealing at 1000 degrees C is the origin of the observed phenomena. The phase transformation epsilon-Fe2O3 - GT alpha-Fe2O3 and crystallization of amorphous silica in quartz and cristobalite were observed in the sample treated at 1100 degrees C.",
journal = "Ceramics International",
title = "Re-formation of metastable epsilon-Fe2O3 in post-annealing of Fe2O3/SiO2 nanostructure: Synthesis, computational particle shape analysis in micrographs and magnetic properties",
volume = "43",
number = "10",
pages = "7497-7507",
doi = "10.1016/j.ceramint.2017.03.030"
}

Nikolić, V. N., Spasojević, V., Panjan, M., Kopanja, L., Mraković, A. Đ.,& Tadić, M.. (2017). Re-formation of metastable epsilon-Fe2O3 in post-annealing of Fe2O3/SiO2 nanostructure: Synthesis, computational particle shape analysis in micrographs and magnetic properties. in Ceramics International, 43(10), 7497-7507.
https://doi.org/10.1016/j.ceramint.2017.03.030

Nikolić VN, Spasojević V, Panjan M, Kopanja L, Mraković AĐ, Tadić M. Re-formation of metastable epsilon-Fe2O3 in post-annealing of Fe2O3/SiO2 nanostructure: Synthesis, computational particle shape analysis in micrographs and magnetic properties. in Ceramics International. 2017;43(10):7497-7507.
doi:10.1016/j.ceramint.2017.03.030 .

Nikolić, Violeta N., Spasojević, Vojislav, Panjan, Matjaž, Kopanja, Lazar, Mraković, Ana Đ., Tadić, Marin, "Re-formation of metastable epsilon-Fe2O3 in post-annealing of Fe2O3/SiO2 nanostructure: Synthesis, computational particle shape analysis in micrographs and magnetic properties" in Ceramics International, 43, no. 10 (2017):7497-7507,
https://doi.org/10.1016/j.ceramint.2017.03.030 . .

TY  - THES
AU  - Nikolić, Violeta N.
PY  - 2017
UR  - http://nardus.mpn.gov.rs/handle/123456789/8942
UR  - http://eteze.bg.ac.rs/application/showtheses?thesesId=5410
UR  - https://fedorabg.bg.ac.rs/fedora/get/o:16782/bdef:Content/download
UR  - https://plus.sr.cobiss.net/opac7/bib/49633807
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8980
AB  - У оквиру ове дисертације су представљени резултати проучавања магнетнихособина наночестичних оксида гвожђа површински модификованих силицијумдиоксидом (SiO2) и олеинском киселином (ОК). Узорци су синтетисани применом триразличита поступка: комбинацијом микроемулзије и сол-гел методе, сол-гелпоступком, и солвотермалном синтезом. У зависности од циља испитивања,структурна и магнетна карактеризација узорака је извршена применом рендгенскедифракције, трансмисионе електронске микроскопије, термијске анализе,инфрацрвене спектроскопије са Fourier-овом трансформацијом, као и применоммагнетних мерења. Посебна пажња је посвећена испитивању магнетног понашањасинтетисаних материјала...
AB  - The aim of this thesis was to investigate magetnic properties of the iron oxidenanoparticles, surface-modified with silica and oleic acid. Samples were prepared by usingthree different synthetic approaches: acid catalysed sol-gel synthesis, combination of themicroemulsion and sol-gel method, and solvothermal synthesis. Structural and magneticinvestigation of the synthesized materials was performed by using X-ray diffraction (XRD),transmission electron microscopy (TEM), thermal analysis (TA), Foruier transform IRspectroscopy(FTIR), and SQUID measurement techniques. Special focus was directed toinvestigation of the magnetic behavior of the examined materials...
PB  - Универзитет у Београду, Факултет за физичку хемију
T2  - Универзитет у Београду
T1  - Магнетне особине наночестица оксида гвожђа површински модификованих силицијум диоксидом и олеинском киселином
UR  - https://hdl.handle.net/21.15107/rcub_nardus_8942
ER  - 

@phdthesis{
author = "Nikolić, Violeta N.",
year = "2017",
abstract = "У оквиру ове дисертације су представљени резултати проучавања магнетнихособина наночестичних оксида гвожђа површински модификованих силицијумдиоксидом (SiO2) и олеинском киселином (ОК). Узорци су синтетисани применом триразличита поступка: комбинацијом микроемулзије и сол-гел методе, сол-гелпоступком, и солвотермалном синтезом. У зависности од циља испитивања,структурна и магнетна карактеризација узорака је извршена применом рендгенскедифракције, трансмисионе електронске микроскопије, термијске анализе,инфрацрвене спектроскопије са Fourier-овом трансформацијом, као и применоммагнетних мерења. Посебна пажња је посвећена испитивању магнетног понашањасинтетисаних материјала..., The aim of this thesis was to investigate magetnic properties of the iron oxidenanoparticles, surface-modified with silica and oleic acid. Samples were prepared by usingthree different synthetic approaches: acid catalysed sol-gel synthesis, combination of themicroemulsion and sol-gel method, and solvothermal synthesis. Structural and magneticinvestigation of the synthesized materials was performed by using X-ray diffraction (XRD),transmission electron microscopy (TEM), thermal analysis (TA), Foruier transform IRspectroscopy(FTIR), and SQUID measurement techniques. Special focus was directed toinvestigation of the magnetic behavior of the examined materials...",
publisher = "Универзитет у Београду, Факултет за физичку хемију",
journal = "Универзитет у Београду",
title = "Магнетне особине наночестица оксида гвожђа површински модификованих силицијум диоксидом и олеинском киселином",
url = "https://hdl.handle.net/21.15107/rcub_nardus_8942"
}

Nikolić, V. N.. (2017). Магнетне особине наночестица оксида гвожђа површински модификованих силицијум диоксидом и олеинском киселином. in Универзитет у Београду
Универзитет у Београду, Факултет за физичку хемију..
https://hdl.handle.net/21.15107/rcub_nardus_8942

Nikolić VN. Магнетне особине наночестица оксида гвожђа површински модификованих силицијум диоксидом и олеинском киселином. in Универзитет у Београду. 2017;.
https://hdl.handle.net/21.15107/rcub_nardus_8942 .

Nikolić, Violeta N., "Магнетне особине наночестица оксида гвожђа површински модификованих силицијум диоксидом и олеинском киселином" in Универзитет у Београду (2017),
https://hdl.handle.net/21.15107/rcub_nardus_8942 .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Tadić, Marin
AU  - Panjan, Matjaž
AU  - Kopanja, Lazar
AU  - Cvjetićanin, Nikola
AU  - Spasojević, Vojislav
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1400
AB  - Magnetic properties of Fe2O3/SiO2 samples were studied after being produced by sol-gel synthesis and formation of epsilon-Fe2O3 polymorph. Samples were thermally treated, using different annealing temperatures and annealing times. The size and morphological characteristics of the iron oxide nanoparticles were examined using a TEM microscope. We used the ellipticity of shapes, which is a measure of how much the shape of a nanoparticle differs from a perfect ellipse, in order to quantitatively describe morphological properties of nanoparticles. Coercivity measurements were used to identify and monitor the formation of the epsilon-iron oxide phase during the thermal treatments (annealing). Coercivity values were in the range from 1.2 to 15.4 kOe, which is in accordance with previous experience regarding the existence of epsilon-Fe2O3. We have determined the optimal formation conditions for the epsilon-Fe2O3 polymorph (t=1050 degrees C for 7 h, H-c=15.4 kOe), as well as the narrow temperature interval (1050-1060 C) in which the polymorph abruptly vanished (H-c=2300 Oe), on the basis of results of the magnetic properties. The threshold temperature for the epsilon-Fe2O3 phase transformation was measured as 1060 degrees C. We found that different annealing temperatures and annealing times significantly affected magnetic properties of the examined samples.
T2  - Ceramics International
T1  - Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of epsilon-Fe2O3 phase
VL  - 43
IS  - 3
SP  - 3147
EP  - 3155
DO  - 10.1016/j.ceramint.2016.11.132
ER  - 

@article{
author = "Nikolić, Violeta N. and Tadić, Marin and Panjan, Matjaž and Kopanja, Lazar and Cvjetićanin, Nikola and Spasojević, Vojislav",
year = "2017",
abstract = "Magnetic properties of Fe2O3/SiO2 samples were studied after being produced by sol-gel synthesis and formation of epsilon-Fe2O3 polymorph. Samples were thermally treated, using different annealing temperatures and annealing times. The size and morphological characteristics of the iron oxide nanoparticles were examined using a TEM microscope. We used the ellipticity of shapes, which is a measure of how much the shape of a nanoparticle differs from a perfect ellipse, in order to quantitatively describe morphological properties of nanoparticles. Coercivity measurements were used to identify and monitor the formation of the epsilon-iron oxide phase during the thermal treatments (annealing). Coercivity values were in the range from 1.2 to 15.4 kOe, which is in accordance with previous experience regarding the existence of epsilon-Fe2O3. We have determined the optimal formation conditions for the epsilon-Fe2O3 polymorph (t=1050 degrees C for 7 h, H-c=15.4 kOe), as well as the narrow temperature interval (1050-1060 C) in which the polymorph abruptly vanished (H-c=2300 Oe), on the basis of results of the magnetic properties. The threshold temperature for the epsilon-Fe2O3 phase transformation was measured as 1060 degrees C. We found that different annealing temperatures and annealing times significantly affected magnetic properties of the examined samples.",
journal = "Ceramics International",
title = "Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of epsilon-Fe2O3 phase",
volume = "43",
number = "3",
pages = "3147-3155",
doi = "10.1016/j.ceramint.2016.11.132"
}

Nikolić, V. N., Tadić, M., Panjan, M., Kopanja, L., Cvjetićanin, N.,& Spasojević, V.. (2017). Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of epsilon-Fe2O3 phase. in Ceramics International, 43(3), 3147-3155.
https://doi.org/10.1016/j.ceramint.2016.11.132

Nikolić VN, Tadić M, Panjan M, Kopanja L, Cvjetićanin N, Spasojević V. Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of epsilon-Fe2O3 phase. in Ceramics International. 2017;43(3):3147-3155.
doi:10.1016/j.ceramint.2016.11.132 .

Nikolić, Violeta N., Tadić, Marin, Panjan, Matjaž, Kopanja, Lazar, Cvjetićanin, Nikola, Spasojević, Vojislav, "Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of epsilon-Fe2O3 phase" in Ceramics International, 43, no. 3 (2017):3147-3155,
https://doi.org/10.1016/j.ceramint.2016.11.132 . .

TY  - JOUR
AU  - Nikolić, Violeta N.
AU  - Perović, Marija M.
AU  - Kusigerski, Vladan
AU  - Bošković, Marko
AU  - Mraković, Ana Đ.
AU  - Blanuša, Jovan
AU  - Spasojević, Vojislav
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/561
AB  - Spherical gamma-Fe2O3 nanoparticles with the narrow size distribution of (5 +/- 1) nm were synthesized by the method of thermal decomposition from iron acetyl acetonate precursor. The existence of super spin-glass state at low temperatures and in low applied magnetic fields was confirmed by DC magnetization measurements on a SQUID magnetometer. The comprehensive investigation of magnetic relaxation dynamics in low-temperature region was conducted through the measurements of single-stop and multiple stop ZFC memory effects, ZFC magnetization relaxation, and AC susceptibility measurements. The experimental findings revealed the peculiar change of magnetic relaxation dynamics at T approximate to 10 K, which arose as a consequence of simultaneous existence of different relaxation processes in Fe2O3 nanoparticle system. Complementarity of the applied measurements was utilized in order to single out distinct relaxation processes as well as to elucidate complex relaxation mechanisms in the investigated interacting nanoparticle system.
T2  - Journal of Nanoparticle Research
T1  - Experimental evidence for simultaneous relaxation processes in super spin glass gamma-Fe2O3 nanoparticle system
VL  - 17
IS  - 3
DO  - 10.1007/s11051-015-2952-2
ER  - 

@article{
author = "Nikolić, Violeta N. and Perović, Marija M. and Kusigerski, Vladan and Bošković, Marko and Mraković, Ana Đ. and Blanuša, Jovan and Spasojević, Vojislav",
year = "2015",
abstract = "Spherical gamma-Fe2O3 nanoparticles with the narrow size distribution of (5 +/- 1) nm were synthesized by the method of thermal decomposition from iron acetyl acetonate precursor. The existence of super spin-glass state at low temperatures and in low applied magnetic fields was confirmed by DC magnetization measurements on a SQUID magnetometer. The comprehensive investigation of magnetic relaxation dynamics in low-temperature region was conducted through the measurements of single-stop and multiple stop ZFC memory effects, ZFC magnetization relaxation, and AC susceptibility measurements. The experimental findings revealed the peculiar change of magnetic relaxation dynamics at T approximate to 10 K, which arose as a consequence of simultaneous existence of different relaxation processes in Fe2O3 nanoparticle system. Complementarity of the applied measurements was utilized in order to single out distinct relaxation processes as well as to elucidate complex relaxation mechanisms in the investigated interacting nanoparticle system.",
journal = "Journal of Nanoparticle Research",
title = "Experimental evidence for simultaneous relaxation processes in super spin glass gamma-Fe2O3 nanoparticle system",
volume = "17",
number = "3",
doi = "10.1007/s11051-015-2952-2"
}

Nikolić, V. N., Perović, M. M., Kusigerski, V., Bošković, M., Mraković, A. Đ., Blanuša, J.,& Spasojević, V.. (2015). Experimental evidence for simultaneous relaxation processes in super spin glass gamma-Fe2O3 nanoparticle system. in Journal of Nanoparticle Research, 17(3).
https://doi.org/10.1007/s11051-015-2952-2

Nikolić VN, Perović MM, Kusigerski V, Bošković M, Mraković AĐ, Blanuša J, Spasojević V. Experimental evidence for simultaneous relaxation processes in super spin glass gamma-Fe2O3 nanoparticle system. in Journal of Nanoparticle Research. 2015;17(3).
doi:10.1007/s11051-015-2952-2 .

Nikolić, Violeta N., Perović, Marija M., Kusigerski, Vladan, Bošković, Marko, Mraković, Ana Đ., Blanuša, Jovan, Spasojević, Vojislav, "Experimental evidence for simultaneous relaxation processes in super spin glass gamma-Fe2O3 nanoparticle system" in Journal of Nanoparticle Research, 17, no. 3 (2015),
https://doi.org/10.1007/s11051-015-2952-2 . .

TY  - JOUR
AU  - Perović, Marija M.
AU  - Kusigerski, Vladan
AU  - Mraković, Ana Đ.
AU  - Spasojević, Vojislav
AU  - Blanuša, Jovan
AU  - Nikolić, Violeta N.
AU  - Schneeweiss, Oldřich B.
AU  - David, B.
AU  - Pizurova, Nadežda
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/429
AB  - Nanorod ferrous oxalate dihydrate (FeC2O4 x 2H(2)O) which had been synthesized by the microemulsion method, was used as a precursor in the thermal decomposition process performed in air atmosphere. The formation of nanocrystalline hematite as the final product was preceded by the appearence of an intermediate product. Comprehensive study comprising several complementary techniques (x-ray diffraction, transmission electron microscopy, selected area electron diffraction, thermogravimetric/differential thermal analyses and SQUID magnetometry) confirmed that the intermediate product corresponds to the poorly crystalline Fe2O3. Due to the specific nanorod shape and poorly crystalline structure, the investigated Fe2O3 showed high coercive field value of similar to 0.5 T at 5 K. Special attention in this study was devoted to the peculiar magnetic properties of poorly crystalline Fe2O3, which were thoroughly investigated by employing sophisticated experimental procedures such as relaxation of thermoremanent magnetization for different cooling fields, zero field and field cooled memory effects as well as aging experiments for different waiting times. At low temperatures and weak applied magnetic fields, the investigated system behaves similarly to spin glasses, manifesting slow, collective relaxation dynamics of magnetic moments through memory, rejuvenation and aging effects.
T2  - Nanotechnology
T1  - The glassy behaviour of poorly crystalline Fe2O3 nanorods obtained by thermal decomposition of ferrous oxalate
VL  - 26
IS  - 11
DO  - 10.1088/0957-4484/26/11/115705
ER  - 

@article{
author = "Perović, Marija M. and Kusigerski, Vladan and Mraković, Ana Đ. and Spasojević, Vojislav and Blanuša, Jovan and Nikolić, Violeta N. and Schneeweiss, Oldřich B. and David, B. and Pizurova, Nadežda",
year = "2015",
abstract = "Nanorod ferrous oxalate dihydrate (FeC2O4 x 2H(2)O) which had been synthesized by the microemulsion method, was used as a precursor in the thermal decomposition process performed in air atmosphere. The formation of nanocrystalline hematite as the final product was preceded by the appearence of an intermediate product. Comprehensive study comprising several complementary techniques (x-ray diffraction, transmission electron microscopy, selected area electron diffraction, thermogravimetric/differential thermal analyses and SQUID magnetometry) confirmed that the intermediate product corresponds to the poorly crystalline Fe2O3. Due to the specific nanorod shape and poorly crystalline structure, the investigated Fe2O3 showed high coercive field value of similar to 0.5 T at 5 K. Special attention in this study was devoted to the peculiar magnetic properties of poorly crystalline Fe2O3, which were thoroughly investigated by employing sophisticated experimental procedures such as relaxation of thermoremanent magnetization for different cooling fields, zero field and field cooled memory effects as well as aging experiments for different waiting times. At low temperatures and weak applied magnetic fields, the investigated system behaves similarly to spin glasses, manifesting slow, collective relaxation dynamics of magnetic moments through memory, rejuvenation and aging effects.",
journal = "Nanotechnology",
title = "The glassy behaviour of poorly crystalline Fe2O3 nanorods obtained by thermal decomposition of ferrous oxalate",
volume = "26",
number = "11",
doi = "10.1088/0957-4484/26/11/115705"
}

Perović, M. M., Kusigerski, V., Mraković, A. Đ., Spasojević, V., Blanuša, J., Nikolić, V. N., Schneeweiss, O. B., David, B.,& Pizurova, N.. (2015). The glassy behaviour of poorly crystalline Fe2O3 nanorods obtained by thermal decomposition of ferrous oxalate. in Nanotechnology, 26(11).
https://doi.org/10.1088/0957-4484/26/11/115705

Perović MM, Kusigerski V, Mraković AĐ, Spasojević V, Blanuša J, Nikolić VN, Schneeweiss OB, David B, Pizurova N. The glassy behaviour of poorly crystalline Fe2O3 nanorods obtained by thermal decomposition of ferrous oxalate. in Nanotechnology. 2015;26(11).
doi:10.1088/0957-4484/26/11/115705 .

Perović, Marija M., Kusigerski, Vladan, Mraković, Ana Đ., Spasojević, Vojislav, Blanuša, Jovan, Nikolić, Violeta N., Schneeweiss, Oldřich B., David, B., Pizurova, Nadežda, "The glassy behaviour of poorly crystalline Fe2O3 nanorods obtained by thermal decomposition of ferrous oxalate" in Nanotechnology, 26, no. 11 (2015),
https://doi.org/10.1088/0957-4484/26/11/115705 . .