TY  - JOUR
AU  - Kosanović, Darko
AU  - Blagojević, Vladimir A.
AU  - Maricić, A.
AU  - Aleksić, S.
AU  - Pavlović, Vera P.
AU  - Pavlović, Vladimir
AU  - Vlahović, Branislav
PY  - 2018
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4755
AB  - Barium hexaferrite ceramics were prepared using mechanically activated mixtures of iron and barium titanate. The 60:40 mass% Fe:BaTiO3 powder mixtures were mechanically activated for different times (100-240 min) and sintered at 1100 and 1200 degrees C in order to determine the influence of mechanical activation of the precursor on the magnetic and dielectric properties of the resulting barium hexaferrite ceramics. The final product contained 84-89 mass% of Ba2Fe22.46O38Ti1.54 phase, with higher content corresponding to longer mechanical activation of the precursor. XRD and Raman measurements indicated that the remainder of the sample consists of leftover BaTiO3 and hematite, which was formed by the oxidation of iron during mechanical activation and sintering in air. Magnetic properties of samples sintered at 1200 degrees C are superior to those sintered at 1100 degrees C, which can be attributed to higher Ba2Fe22.46O38Ti1.54 phase content. The position of the Curie temperature in 350-420 degrees C temperature region is consistent with 0.8:1 ratio of Ti to Ba. Maximum magnetization was observed for samples activated for 120 min. Dielectric properties of samples sintered at 1200 degrees C showed a dependence on frequency, with a significant drop in relative permittivity with an increase in frequency in the low-frequency region, and relatively constant values of relative permittivity in the high-frequency region. The tangent loss showed a decrease with increase in frequency, where peaks corresponding to the resonance of the electron hopping frequency with the external field were observed in the samples corresponding to the longer mechanical activation. Dielectric properties showed relatively small changes for samples activated longer than 150 min.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Influence of mechanical activation on functional properties of barium hexaferrite ceramics
EP  - 6672
IS  - 6
SP  - 6666
VL  - 44
DO  - 10.1016/j.ceramint.2018.01.078
ER  - 

@article{
author = "Kosanović, Darko and Blagojević, Vladimir A. and Maricić, A. and Aleksić, S. and Pavlović, Vera P. and Pavlović, Vladimir and Vlahović, Branislav",
year = "2018",
abstract = "Barium hexaferrite ceramics were prepared using mechanically activated mixtures of iron and barium titanate. The 60:40 mass% Fe:BaTiO3 powder mixtures were mechanically activated for different times (100-240 min) and sintered at 1100 and 1200 degrees C in order to determine the influence of mechanical activation of the precursor on the magnetic and dielectric properties of the resulting barium hexaferrite ceramics. The final product contained 84-89 mass% of Ba2Fe22.46O38Ti1.54 phase, with higher content corresponding to longer mechanical activation of the precursor. XRD and Raman measurements indicated that the remainder of the sample consists of leftover BaTiO3 and hematite, which was formed by the oxidation of iron during mechanical activation and sintering in air. Magnetic properties of samples sintered at 1200 degrees C are superior to those sintered at 1100 degrees C, which can be attributed to higher Ba2Fe22.46O38Ti1.54 phase content. The position of the Curie temperature in 350-420 degrees C temperature region is consistent with 0.8:1 ratio of Ti to Ba. Maximum magnetization was observed for samples activated for 120 min. Dielectric properties of samples sintered at 1200 degrees C showed a dependence on frequency, with a significant drop in relative permittivity with an increase in frequency in the low-frequency region, and relatively constant values of relative permittivity in the high-frequency region. The tangent loss showed a decrease with increase in frequency, where peaks corresponding to the resonance of the electron hopping frequency with the external field were observed in the samples corresponding to the longer mechanical activation. Dielectric properties showed relatively small changes for samples activated longer than 150 min.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Influence of mechanical activation on functional properties of barium hexaferrite ceramics",
pages = "6672-6666",
number = "6",
volume = "44",
doi = "10.1016/j.ceramint.2018.01.078"
}

Kosanović, D., Blagojević, V. A., Maricić, A., Aleksić, S., Pavlović, V. P., Pavlović, V.,& Vlahović, B.. (2018). Influence of mechanical activation on functional properties of barium hexaferrite ceramics. in Ceramics International
Elsevier Sci Ltd, Oxford., 44(6), 6666-6672.
https://doi.org/10.1016/j.ceramint.2018.01.078

Kosanović D, Blagojević VA, Maricić A, Aleksić S, Pavlović VP, Pavlović V, Vlahović B. Influence of mechanical activation on functional properties of barium hexaferrite ceramics. in Ceramics International. 2018;44(6):6666-6672.
doi:10.1016/j.ceramint.2018.01.078 .

Kosanović, Darko, Blagojević, Vladimir A., Maricić, A., Aleksić, S., Pavlović, Vera P., Pavlović, Vladimir, Vlahović, Branislav, "Influence of mechanical activation on functional properties of barium hexaferrite ceramics" in Ceramics International, 44, no. 6 (2018):6666-6672,
https://doi.org/10.1016/j.ceramint.2018.01.078 . .

TY  - JOUR
AU  - Kosanović, Darko
AU  - Obradović, N.
AU  - Pavlović, Vera P.
AU  - Marković, S.
AU  - Maricić, A.
AU  - Rasić, G.
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir
AU  - Ristić, M.M.
PY  - 2016
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4010
AB  - Crystal structure and morphology of mechanically activated nanocrystalline Fe/BaTiO3 was investigated using a combination of spectroscopic and microscopic methods. These show that mechanical activation led to the creation of new surfaces and the comminution of the initial powder particles. Prolonged milling resulted in formation of larger agglomerates of BaTiO3 and bimodal particle size distribution, where BaTiO3 particles were significantly larger than those of iron-containing phases. Milling times of 210 min and above lead to a significant decrease in temperature of the oxidation of iron in the sample, indicating abrupt change in reactivity. Raman spectroscopy analysis has revealed that activation had a pronounced influence on Fe/BaTiO3 lattice, thereby affecting both the stability of the crystal structure and the phase transition phenomena.
PB  - Elsevier, Amsterdam
T2  - Materials Science and Engineering B-Advanced Functional Solid-State Materials
T1  - The influence of mechanical activation on the morphological changes of Fe/BaTiO3 powder
EP  - 95
SP  - 89
VL  - 212
DO  - 10.1016/j.mseb.2016.07.016
ER  - 

@article{
author = "Kosanović, Darko and Obradović, N. and Pavlović, Vera P. and Marković, S. and Maricić, A. and Rasić, G. and Vlahović, Branislav and Pavlović, Vladimir and Ristić, M.M.",
year = "2016",
abstract = "Crystal structure and morphology of mechanically activated nanocrystalline Fe/BaTiO3 was investigated using a combination of spectroscopic and microscopic methods. These show that mechanical activation led to the creation of new surfaces and the comminution of the initial powder particles. Prolonged milling resulted in formation of larger agglomerates of BaTiO3 and bimodal particle size distribution, where BaTiO3 particles were significantly larger than those of iron-containing phases. Milling times of 210 min and above lead to a significant decrease in temperature of the oxidation of iron in the sample, indicating abrupt change in reactivity. Raman spectroscopy analysis has revealed that activation had a pronounced influence on Fe/BaTiO3 lattice, thereby affecting both the stability of the crystal structure and the phase transition phenomena.",
publisher = "Elsevier, Amsterdam",
journal = "Materials Science and Engineering B-Advanced Functional Solid-State Materials",
title = "The influence of mechanical activation on the morphological changes of Fe/BaTiO3 powder",
pages = "95-89",
volume = "212",
doi = "10.1016/j.mseb.2016.07.016"
}

Kosanović, D., Obradović, N., Pavlović, V. P., Marković, S., Maricić, A., Rasić, G., Vlahović, B., Pavlović, V.,& Ristić, M.M.. (2016). The influence of mechanical activation on the morphological changes of Fe/BaTiO3 powder. in Materials Science and Engineering B-Advanced Functional Solid-State Materials
Elsevier, Amsterdam., 212, 89-95.
https://doi.org/10.1016/j.mseb.2016.07.016

Kosanović D, Obradović N, Pavlović VP, Marković S, Maricić A, Rasić G, Vlahović B, Pavlović V, Ristić M. The influence of mechanical activation on the morphological changes of Fe/BaTiO3 powder. in Materials Science and Engineering B-Advanced Functional Solid-State Materials. 2016;212:89-95.
doi:10.1016/j.mseb.2016.07.016 .

Kosanović, Darko, Obradović, N., Pavlović, Vera P., Marković, S., Maricić, A., Rasić, G., Vlahović, Branislav, Pavlović, Vladimir, Ristić, M.M., "The influence of mechanical activation on the morphological changes of Fe/BaTiO3 powder" in Materials Science and Engineering B-Advanced Functional Solid-State Materials, 212 (2016):89-95,
https://doi.org/10.1016/j.mseb.2016.07.016 . .

TY  - JOUR
AU  - Kosanović, Darko
AU  - Zivojinović, J.
AU  - Obradović, N.
AU  - Pavlović, Vera P.
AU  - Pavlović, Vladimir
AU  - Peles, A.
AU  - Ristić, M.M.
PY  - 2014
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/3418
AB  - Ferroelectric barium strontium titanate (Ba0.77Sr0.23TiO3), BST, was prepared by solid-state reactions using as the starting compounds powder of barium carbonate (BaCO3), strontium carbonate (SrCO3) and titanium dioxide (TiO2 anatase). Non-activated mixtures and mixtures mechanically activated in a high-energy planetary ball mill (0, 5, 10, 20, 40, 80 and 120 min) were sintered at 1100, 1200, 1300 and 1400 degrees C for 2 h in air atmosphere. Defects and the effect of the beginning of the sintering process on the microstructure were investigated by scanning electron microscopy (SEM). Electrical measurements (loss tangent and resistivity as the function of frequency X-C =f(log nu)) were performed for ceramics sintered at 1400 degrees C for 2 h. It has been found that mechanical activation can reduce the sintering temperature by around 100 degrees C, which leads to significant energy savings. Furthermore, activated for 80 min and sintered at. 1400 degrees C for 2 h exhibit the largest density values and have about 36% lower dielectric loss at a frequency of 1 kHz and about 57% at a frequency of 10 kHz than the samples obtained from the initial non-activated powder sintered under the same conditions.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - The influence of mechanical activation on the electrical properties of Ba0.77Sr0.23TiO3 ceramics
EP  - 11888
IS  - 8
SP  - 11883
VL  - 40
DO  - 10.1016/j.ceramint.2014.04.023
ER  - 

@article{
author = "Kosanović, Darko and Zivojinović, J. and Obradović, N. and Pavlović, Vera P. and Pavlović, Vladimir and Peles, A. and Ristić, M.M.",
year = "2014",
abstract = "Ferroelectric barium strontium titanate (Ba0.77Sr0.23TiO3), BST, was prepared by solid-state reactions using as the starting compounds powder of barium carbonate (BaCO3), strontium carbonate (SrCO3) and titanium dioxide (TiO2 anatase). Non-activated mixtures and mixtures mechanically activated in a high-energy planetary ball mill (0, 5, 10, 20, 40, 80 and 120 min) were sintered at 1100, 1200, 1300 and 1400 degrees C for 2 h in air atmosphere. Defects and the effect of the beginning of the sintering process on the microstructure were investigated by scanning electron microscopy (SEM). Electrical measurements (loss tangent and resistivity as the function of frequency X-C =f(log nu)) were performed for ceramics sintered at 1400 degrees C for 2 h. It has been found that mechanical activation can reduce the sintering temperature by around 100 degrees C, which leads to significant energy savings. Furthermore, activated for 80 min and sintered at. 1400 degrees C for 2 h exhibit the largest density values and have about 36% lower dielectric loss at a frequency of 1 kHz and about 57% at a frequency of 10 kHz than the samples obtained from the initial non-activated powder sintered under the same conditions.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "The influence of mechanical activation on the electrical properties of Ba0.77Sr0.23TiO3 ceramics",
pages = "11888-11883",
number = "8",
volume = "40",
doi = "10.1016/j.ceramint.2014.04.023"
}

Kosanović, D., Zivojinović, J., Obradović, N., Pavlović, V. P., Pavlović, V., Peles, A.,& Ristić, M.M.. (2014). The influence of mechanical activation on the electrical properties of Ba0.77Sr0.23TiO3 ceramics. in Ceramics International
Elsevier Sci Ltd, Oxford., 40(8), 11883-11888.
https://doi.org/10.1016/j.ceramint.2014.04.023

Kosanović D, Zivojinović J, Obradović N, Pavlović VP, Pavlović V, Peles A, Ristić M. The influence of mechanical activation on the electrical properties of Ba0.77Sr0.23TiO3 ceramics. in Ceramics International. 2014;40(8):11883-11888.
doi:10.1016/j.ceramint.2014.04.023 .

Kosanović, Darko, Zivojinović, J., Obradović, N., Pavlović, Vera P., Pavlović, Vladimir, Peles, A., Ristić, M.M., "The influence of mechanical activation on the electrical properties of Ba0.77Sr0.23TiO3 ceramics" in Ceramics International, 40, no. 8 (2014):11883-11888,
https://doi.org/10.1016/j.ceramint.2014.04.023 . .