TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Smith, Steven
AU  - Mirković, Miljana M.
AU  - Peleš Tadić, Adriana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12795
AB  - Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.
T2  - Ceramics International
T1  - Spark plasma sintering of magnesium titanate ceramics
IS  - InPress
DO  - 10.1016/j.ceramint.2024.02.004
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William G. and Smith, Steven and Mirković, Miljana M. and Peleš Tadić, Adriana and Petrović, Jovana and Đorđević, Antonije",
year = "2024",
abstract = "Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.",
journal = "Ceramics International",
title = "Spark plasma sintering of magnesium titanate ceramics",
number = "InPress",
doi = "10.1016/j.ceramint.2024.02.004"
}

Filipović, S., Obradović, N., Fahrenholtz, W. G., Smith, S., Mirković, M. M., Peleš Tadić, A., Petrović, J.,& Đorđević, A.. (2024). Spark plasma sintering of magnesium titanate ceramics. in Ceramics International(InPress).
https://doi.org/10.1016/j.ceramint.2024.02.004

Filipović S, Obradović N, Fahrenholtz WG, Smith S, Mirković MM, Peleš Tadić A, Petrović J, Đorđević A. Spark plasma sintering of magnesium titanate ceramics. in Ceramics International. 2024;(InPress).
doi:10.1016/j.ceramint.2024.02.004 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William G., Smith, Steven, Mirković, Miljana M., Peleš Tadić, Adriana, Petrović, Jovana, Đorđević, Antonije, "Spark plasma sintering of magnesium titanate ceramics" in Ceramics International, no. InPress (2024),
https://doi.org/10.1016/j.ceramint.2024.02.004 . .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Corlett, Cole
AU  - Fahrenholtz, William G.
AU  - Rosenschon, Martin
AU  - Füglein, Ekkehard
AU  - Dojčilović, Radovan
AU  - Tošić, Dragana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir B.
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12400
AB  - Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.
T2  - Journal of Applied Polymer Science
T1  - Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite
DO  - 10.1002/app.55040
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Corlett, Cole and Fahrenholtz, William G. and Rosenschon, Martin and Füglein, Ekkehard and Dojčilović, Radovan and Tošić, Dragana and Petrović, Jovana and Đorđević, Antonije and Vlahović, Branislav and Pavlović, Vladimir B.",
year = "2023",
abstract = "Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.",
journal = "Journal of Applied Polymer Science",
title = "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite",
doi = "10.1002/app.55040"
}

Filipović, S., Obradović, N., Corlett, C., Fahrenholtz, W. G., Rosenschon, M., Füglein, E., Dojčilović, R., Tošić, D., Petrović, J., Đorđević, A., Vlahović, B.,& Pavlović, V. B.. (2023). Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science.
https://doi.org/10.1002/app.55040

Filipović S, Obradović N, Corlett C, Fahrenholtz WG, Rosenschon M, Füglein E, Dojčilović R, Tošić D, Petrović J, Đorđević A, Vlahović B, Pavlović VB. Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science. 2023;.
doi:10.1002/app.55040 .

Filipović, Suzana, Obradović, Nina, Corlett, Cole, Fahrenholtz, William G., Rosenschon, Martin, Füglein, Ekkehard, Dojčilović, Radovan, Tošić, Dragana, Petrović, Jovana, Đorđević, Antonije, Vlahović, Branislav, Pavlović, Vladimir B., "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite" in Journal of Applied Polymer Science (2023),
https://doi.org/10.1002/app.55040 . .

TY  - CONF
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William G.
AU  - Smith, Steven
AU  - Mirković, M.
AU  - Peleš, Adriana
AU  - Tadić, Nenad
AU  - Đorđević, Antonije
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10825
AB  - Perovskite ceramic material based on MgTiO3 is used in various types of electronic devices owing to its dielectric properties, high dielectric constant, and low losses. These features can be tailored by setting preparation conditions. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. First, the mechanical activation in the highenergy ball mill was applied on the powder of MgO-TiO2 mixed in mole ratio 1:1. Prepared powder mixtures, activated for different times, were SPS sintered, at 1200 o C with a heating rate of 100o C/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied, and dwelled at this condition for 5 min, followed by cooling to room temperature at 5o C/min. The starting powders, activated mixtures, and sintered ceramics bodies were investigated by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was noticed for the nonmilled ceramics. In the samples obtained from milled powders, MgTi2O5 was detected in EDS spectra in a lower amount, below the threshold of the XRD method. Dielectric measurements were performed at a wide range of frequencies and temperatures. The highest value of the hardness was obtained from powder milled for 15 min before SPS.
PB  - Belgrade : Serbian Ceramic Society
C3  - Advanced Ceramics and Application : 10th Serbian Ceramic Society Conference : program and the book of abstracts; September 26-27, 2022; Belgrade
T1  - Effect of high energy ball milling on sintering of MgO-TiO2 system
SP  - 88
UR  - https://hdl.handle.net/21.15107/rcub_vinar_10825
ER  - 

@conference{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William G. and Smith, Steven and Mirković, M. and Peleš, Adriana and Tadić, Nenad and Đorđević, Antonije",
year = "2022",
abstract = "Perovskite ceramic material based on MgTiO3 is used in various types of electronic devices owing to its dielectric properties, high dielectric constant, and low losses. These features can be tailored by setting preparation conditions. Densification of magnesium titanate by Spark Plasma Sintering (SPS) was the aim of this work. First, the mechanical activation in the highenergy ball mill was applied on the powder of MgO-TiO2 mixed in mole ratio 1:1. Prepared powder mixtures, activated for different times, were SPS sintered, at 1200 o C with a heating rate of 100o C/min. After reaching the desired temperature, a uniaxial pressure of 50 MPa was applied, and dwelled at this condition for 5 min, followed by cooling to room temperature at 5o C/min. The starting powders, activated mixtures, and sintered ceramics bodies were investigated by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was noticed for the nonmilled ceramics. In the samples obtained from milled powders, MgTi2O5 was detected in EDS spectra in a lower amount, below the threshold of the XRD method. Dielectric measurements were performed at a wide range of frequencies and temperatures. The highest value of the hardness was obtained from powder milled for 15 min before SPS.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Advanced Ceramics and Application : 10th Serbian Ceramic Society Conference : program and the book of abstracts; September 26-27, 2022; Belgrade",
title = "Effect of high energy ball milling on sintering of MgO-TiO2 system",
pages = "88",
url = "https://hdl.handle.net/21.15107/rcub_vinar_10825"
}

Filipović, S., Obradović, N., Fahrenholtz, W. G., Smith, S., Mirković, M., Peleš, A., Tadić, N.,& Đorđević, A.. (2022). Effect of high energy ball milling on sintering of MgO-TiO2 system. in Advanced Ceramics and Application : 10th Serbian Ceramic Society Conference : program and the book of abstracts; September 26-27, 2022; Belgrade
Belgrade : Serbian Ceramic Society., 88.
https://hdl.handle.net/21.15107/rcub_vinar_10825

Filipović S, Obradović N, Fahrenholtz WG, Smith S, Mirković M, Peleš A, Tadić N, Đorđević A. Effect of high energy ball milling on sintering of MgO-TiO2 system. in Advanced Ceramics and Application : 10th Serbian Ceramic Society Conference : program and the book of abstracts; September 26-27, 2022; Belgrade. 2022;:88.
https://hdl.handle.net/21.15107/rcub_vinar_10825 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William G., Smith, Steven, Mirković, M., Peleš, Adriana, Tadić, Nenad, Đorđević, Antonije, "Effect of high energy ball milling on sintering of MgO-TiO2 system" in Advanced Ceramics and Application : 10th Serbian Ceramic Society Conference : program and the book of abstracts; September 26-27, 2022; Belgrade (2022):88,
https://hdl.handle.net/21.15107/rcub_vinar_10825 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Pavlović, Vladimir B.
AU  - Mitrić, Miodrag
AU  - Đorđević, Antonije R.
AU  - Kachlik, M.
AU  - Maca, Karel
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1037
AB  - The aim of this study is to explore the influence of the processing route on the structural and physical properties of bulk MgTiO3 ceramics. Commercially available MgO and TiO2 powders were mechanically activated in a planetary ball mill. Green bodies were formed by an isostatic pressure of 300 MPa. The sintering of these samples was done either by the Two-Step Sintering (TSS) approach or by conventional pressureless sintering followed by Hot Isostatic Pressing (post-HIPing). The first set of compacts was sintered by TSS in air at 1300 degrees C for 30 min and the next step was performed at 1200 degrees C for 20 h. The density of the obtained samples after the two-step sintering reached almost 90% of the theoretical density (%TD). The second set of compacts was sintered at 1400 degrees C for 30 min in air. The samples without open porosity were post-sintered by the HIP at 1200 degrees C for 2 h in an argon atmosphere at a pressure of 200 MPa. The density significantly increased up to 96%TD. The differences between samples prepared by these two techniques were also analyzed by XRD and SEM. The lattice vibration spectra were obtained using Raman spectroscopy and they indicate a high degree of lattice disorder, as well as high values of the oxygen vacancy concentration. Electrical characteristic were established in the frequency range from 10 kHz to 10 GHz. The choice of the processing route had considerable influence on structural and physical properties of MgTiO3 ceramics. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
PB  - Elsevier
T2  - Ceramics International
T1  - Effect of consolidation parameters on structural, microstructural and electrical properties of magnesium titanate ceramics
VL  - 42
IS  - 8
SP  - 9887
EP  - 9898
DO  - 10.1016/j.ceramint.2016.03.088
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Pavlović, Vladimir B. and Mitrić, Miodrag and Đorđević, Antonije R. and Kachlik, M. and Maca, Karel",
year = "2016",
abstract = "The aim of this study is to explore the influence of the processing route on the structural and physical properties of bulk MgTiO3 ceramics. Commercially available MgO and TiO2 powders were mechanically activated in a planetary ball mill. Green bodies were formed by an isostatic pressure of 300 MPa. The sintering of these samples was done either by the Two-Step Sintering (TSS) approach or by conventional pressureless sintering followed by Hot Isostatic Pressing (post-HIPing). The first set of compacts was sintered by TSS in air at 1300 degrees C for 30 min and the next step was performed at 1200 degrees C for 20 h. The density of the obtained samples after the two-step sintering reached almost 90% of the theoretical density (%TD). The second set of compacts was sintered at 1400 degrees C for 30 min in air. The samples without open porosity were post-sintered by the HIP at 1200 degrees C for 2 h in an argon atmosphere at a pressure of 200 MPa. The density significantly increased up to 96%TD. The differences between samples prepared by these two techniques were also analyzed by XRD and SEM. The lattice vibration spectra were obtained using Raman spectroscopy and they indicate a high degree of lattice disorder, as well as high values of the oxygen vacancy concentration. Electrical characteristic were established in the frequency range from 10 kHz to 10 GHz. The choice of the processing route had considerable influence on structural and physical properties of MgTiO3 ceramics. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Effect of consolidation parameters on structural, microstructural and electrical properties of magnesium titanate ceramics",
volume = "42",
number = "8",
pages = "9887-9898",
doi = "10.1016/j.ceramint.2016.03.088"
}

Filipović, S., Obradović, N., Pavlović, V. B., Mitrić, M., Đorđević, A. R., Kachlik, M.,& Maca, K.. (2016). Effect of consolidation parameters on structural, microstructural and electrical properties of magnesium titanate ceramics. in Ceramics International
Elsevier., 42(8), 9887-9898.
https://doi.org/10.1016/j.ceramint.2016.03.088

Filipović S, Obradović N, Pavlović VB, Mitrić M, Đorđević AR, Kachlik M, Maca K. Effect of consolidation parameters on structural, microstructural and electrical properties of magnesium titanate ceramics. in Ceramics International. 2016;42(8):9887-9898.
doi:10.1016/j.ceramint.2016.03.088 .

Filipović, Suzana, Obradović, Nina, Pavlović, Vladimir B., Mitrić, Miodrag, Đorđević, Antonije R., Kachlik, M., Maca, Karel, "Effect of consolidation parameters on structural, microstructural and electrical properties of magnesium titanate ceramics" in Ceramics International, 42, no. 8 (2016):9887-9898,
https://doi.org/10.1016/j.ceramint.2016.03.088 . .