TY  - JOUR
AU  - Nikolić, M.V.
AU  - Vasiljević, Zorka
AU  - Luković, M.D.
AU  - Pavlović, Vera P.
AU  - Krstić, J.B.
AU  - Vujancević, J.
AU  - Tadić, N.
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir
PY  - 2019
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5136
AB  - Zinc ferrite nanocrystalline powder was obtained by solid state synthesis of starting zinc oxide and hematite nanopowders. Field emission scanning electron microscopy and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the formation of nanocrystalline zinc-ferrite powder with a mixed spinel structure with small amounts of remaining zinc oxide and hematite as impurities. Thick film paste was formed and screen printed on test interdigitated PdAg electrodes on alumina substrate. Formation of a porous nanocrystalline structure was confirmed by scanning electron microscopy and Hg porosimetry. Humidity sensing properties of zinc ferrite thick films were investigated by monitoring the change in impedance in the relative humidity interval 30%-90% in the frequency range 42 Hz-1 MHz at room temperature (25°C) and 50°C. At 42 Hz at both analyzed temperatures the impedance reduced ~46 times in the humidity range 30%-90%. The dominant influence of grain boundaries was confirmed by analysis of complex impedance with an equivalent circuit.
PB  - Blackwell Publishing Ltd
T2  - International Journal of Applied Ceramic Technology
T1  - Investigation of ZnFe 2 O 4 spinel ferrite nanocrystalline screen-printed thick films for application in humidity sensing
EP  - 993
IS  - 3
SP  - 981
VL  - 16
DO  - 10.1111/ijac.13190
ER  - 

@article{
author = "Nikolić, M.V. and Vasiljević, Zorka and Luković, M.D. and Pavlović, Vera P. and Krstić, J.B. and Vujancević, J. and Tadić, N. and Vlahović, Branislav and Pavlović, Vladimir",
year = "2019",
abstract = "Zinc ferrite nanocrystalline powder was obtained by solid state synthesis of starting zinc oxide and hematite nanopowders. Field emission scanning electron microscopy and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the formation of nanocrystalline zinc-ferrite powder with a mixed spinel structure with small amounts of remaining zinc oxide and hematite as impurities. Thick film paste was formed and screen printed on test interdigitated PdAg electrodes on alumina substrate. Formation of a porous nanocrystalline structure was confirmed by scanning electron microscopy and Hg porosimetry. Humidity sensing properties of zinc ferrite thick films were investigated by monitoring the change in impedance in the relative humidity interval 30%-90% in the frequency range 42 Hz-1 MHz at room temperature (25°C) and 50°C. At 42 Hz at both analyzed temperatures the impedance reduced ~46 times in the humidity range 30%-90%. The dominant influence of grain boundaries was confirmed by analysis of complex impedance with an equivalent circuit.",
publisher = "Blackwell Publishing Ltd",
journal = "International Journal of Applied Ceramic Technology",
title = "Investigation of ZnFe 2 O 4 spinel ferrite nanocrystalline screen-printed thick films for application in humidity sensing",
pages = "993-981",
number = "3",
volume = "16",
doi = "10.1111/ijac.13190"
}

Nikolić, M.V., Vasiljević, Z., Luković, M.D., Pavlović, V. P., Krstić, J.B., Vujancević, J., Tadić, N., Vlahović, B.,& Pavlović, V.. (2019). Investigation of ZnFe 2 O 4 spinel ferrite nanocrystalline screen-printed thick films for application in humidity sensing. in International Journal of Applied Ceramic Technology
Blackwell Publishing Ltd., 16(3), 981-993.
https://doi.org/10.1111/ijac.13190

Nikolić M, Vasiljević Z, Luković M, Pavlović VP, Krstić J, Vujancević J, Tadić N, Vlahović B, Pavlović V. Investigation of ZnFe 2 O 4 spinel ferrite nanocrystalline screen-printed thick films for application in humidity sensing. in International Journal of Applied Ceramic Technology. 2019;16(3):981-993.
doi:10.1111/ijac.13190 .

Nikolić, M.V., Vasiljević, Zorka, Luković, M.D., Pavlović, Vera P., Krstić, J.B., Vujancević, J., Tadić, N., Vlahović, Branislav, Pavlović, Vladimir, "Investigation of ZnFe 2 O 4 spinel ferrite nanocrystalline screen-printed thick films for application in humidity sensing" in International Journal of Applied Ceramic Technology, 16, no. 3 (2019):981-993,
https://doi.org/10.1111/ijac.13190 . .

TY  - JOUR
AU  - Nikolić, M.V.
AU  - Sekulić, D.L.
AU  - Vasiljević, Zorka
AU  - Luković, M.D.
AU  - Pavlović, Vladimir
AU  - Aleksić, O.S.
PY  - 2017
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4367
AB  - In this work we have investigated changes in dielectric properties, electrical conductivity and complex impedance of Fe2TiO5 nanopowder compacts and bulk samples as a function of elevated temperature (room to 423 K compacts, to 443 K bulk samples), frequency (100 Hz-1 MHz) and composition (starting molar ratio of Fe2O3 and TiO2 1:1-PSB11 and 1:1.5-PSB115). XRD, SEM and TEM analysis of PSB11 and PSB115 powders obtained by a simple solid state process from starting hematite and anatase nanopowders confirmed the formation of nanostructured orthorhombic pseudobrookite with small amounts of excess hematite and rutile. The dielectric constant decreased with frequency and temperature for both compacts and bulk samples. Higher values were determined for bulk samples also reflecting the influence of sample composition. Change in the dielectric loss also reflected the influence of sample composition showing one maximum at high frequencies for compacts, and two maxima at room temperature for bulk samples. Complex impedance was analyzed using equivalent circuits and showed in the case of compacts the influence of both grain and grain boundary components, while in the case of bulk samples the dominant influence of grain boundaries. The temperature dependence of the determined grain and grain boundary resistance for compacts and grain boundary resistance for bulk samples was analyzed using the adiabatic small polaron hopping model enabling determination of activation energies for conduction, while the temperature dependence of relaxation times enabled determination of activation energies for relaxation. Changes in electrical conductivity for compacts and bulk samples followed Jonscher's power law. The change of the determined frequency constant with temperature showed that at elevated temperatures the quantum mechanical-tunneling model for the case of small polaron hopping explains the conduction mechanism occurring in both compacts and bulk samples.
PB  - Springer, Dordrecht
T2  - Journal of Materials Science-Materials in Electronics
T1  - Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures
EP  - 4806
IS  - 6
SP  - 4796
VL  - 28
DO  - 10.1007/s10854-016-6125-6
ER  - 

@article{
author = "Nikolić, M.V. and Sekulić, D.L. and Vasiljević, Zorka and Luković, M.D. and Pavlović, Vladimir and Aleksić, O.S.",
year = "2017",
abstract = "In this work we have investigated changes in dielectric properties, electrical conductivity and complex impedance of Fe2TiO5 nanopowder compacts and bulk samples as a function of elevated temperature (room to 423 K compacts, to 443 K bulk samples), frequency (100 Hz-1 MHz) and composition (starting molar ratio of Fe2O3 and TiO2 1:1-PSB11 and 1:1.5-PSB115). XRD, SEM and TEM analysis of PSB11 and PSB115 powders obtained by a simple solid state process from starting hematite and anatase nanopowders confirmed the formation of nanostructured orthorhombic pseudobrookite with small amounts of excess hematite and rutile. The dielectric constant decreased with frequency and temperature for both compacts and bulk samples. Higher values were determined for bulk samples also reflecting the influence of sample composition. Change in the dielectric loss also reflected the influence of sample composition showing one maximum at high frequencies for compacts, and two maxima at room temperature for bulk samples. Complex impedance was analyzed using equivalent circuits and showed in the case of compacts the influence of both grain and grain boundary components, while in the case of bulk samples the dominant influence of grain boundaries. The temperature dependence of the determined grain and grain boundary resistance for compacts and grain boundary resistance for bulk samples was analyzed using the adiabatic small polaron hopping model enabling determination of activation energies for conduction, while the temperature dependence of relaxation times enabled determination of activation energies for relaxation. Changes in electrical conductivity for compacts and bulk samples followed Jonscher's power law. The change of the determined frequency constant with temperature showed that at elevated temperatures the quantum mechanical-tunneling model for the case of small polaron hopping explains the conduction mechanism occurring in both compacts and bulk samples.",
publisher = "Springer, Dordrecht",
journal = "Journal of Materials Science-Materials in Electronics",
title = "Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures",
pages = "4806-4796",
number = "6",
volume = "28",
doi = "10.1007/s10854-016-6125-6"
}

Nikolić, M.V., Sekulić, D.L., Vasiljević, Z., Luković, M.D., Pavlović, V.,& Aleksić, O.S.. (2017). Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures. in Journal of Materials Science-Materials in Electronics
Springer, Dordrecht., 28(6), 4796-4806.
https://doi.org/10.1007/s10854-016-6125-6

Nikolić M, Sekulić D, Vasiljević Z, Luković M, Pavlović V, Aleksić O. Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures. in Journal of Materials Science-Materials in Electronics. 2017;28(6):4796-4806.
doi:10.1007/s10854-016-6125-6 .

Nikolić, M.V., Sekulić, D.L., Vasiljević, Zorka, Luković, M.D., Pavlović, Vladimir, Aleksić, O.S., "Dielectric properties, complex impedance and electrical conductivity of Fe2TiO5 nanopowder compacts and bulk samples at elevated temperatures" in Journal of Materials Science-Materials in Electronics, 28, no. 6 (2017):4796-4806,
https://doi.org/10.1007/s10854-016-6125-6 . .