"Thermal diffusivity and electron transport properties of NTC samples obtained by photoacoustic method

Poster presented at the Seventh Yugoslav Materials Research Society Conference - YUCOMAT 2005, Herceg Novi, Crna Gora, September 12-16, 2005

3 Structural, morphological and electrical properties of sintered Fe2O3/TiO2 nanopowder mixtures

Starting nanopowders of TiO2 (anatase 99.7%) and a-Fe2O3 (hematite) were mixed in the weight ratio 60:40 and 40:60. Green samples were sintered in the temperature range 750-1250oC in air. Structural, morphological and electrical studies were carried out using XRD, SEM and EDS analysis and Hall measurements with the aim of analyzing the influence of the starting nanopowder structure on the resulting sample composition, density, grain size and electrical resistivity. Compared to pure anatase samples, the presence of hematite lowered the temperature of completion of the anatase to rutile phase transformation to 850oC. Formation of pseudobrookite was also noted at this temperature. Further increase in the sintering temperature lead to increase in sample density and grain size and decrease in the electric resistivity, Hall coefficient and mobility

"Thermal diffusivity and electron transport properties of NTC samples obtained by photoacoustic method

Poster presented at the Seventh Yugoslav Materials Research Society Conference - YUCOMAT 2005, Herceg Novi, Crna Gora, September 12-16, 2005

Segmented thermistors printed using NTC nanometric paste on alumina and Sr-ferrite substrates

Poster presented at 12th Annual Conference of the Materials Research Society of Serbia - YUCOMAT 2010, Herceg Novi, Montenegro, 6–10. septembar 2010

Microstructure development and electrical properties of NiO doped alpha-Fe2O3

Poster presented at the 4th Serbian Congress for Microscopy, Belgrade, Serbia, 2010, October 11-12, 201

Humidity sensing potential of Fe2TiO5—pseudobrookite

Bulk samples of pseudobrookite with an orthorhombic crystal structure were prepared by sintering a mixture of starting hematite and anatase nano powders in the weight ratio 60:40 at three different sintering temperatures (950, 1050 and 1150 °C) resulting in different microstructures determined by SEM analysis. Humidity sensing properties of pseudobrookite were investigated by measuring changes in electrical properties at operating temperatures of 20, 40 and 60 °C in the frequency range 100 Hz–100 kHz in the relative humidity range 30–90% in a climatic chamber. At 100 Hz, and 20 °C the impedance of pseudobrookite sintered at 1150 °C reduced over 5 times in the humidity range 40–90%, and 7 times at 60 °C for pseudobrookite sintered at 950 °C. Detailed analysis of dielectric properties showed that the dielectric constant increased noticeably with increase in humidity at low frequencies. Electrical conductivity change with frequency followed the Jonscher power law, and increased with increase in relative humidity. The determined frequency constant reduced with increase in sample temperature and increase in relative humidity. The conduction mechanism can be explained using the correlated barrier hopping model. Analysis of complex impedance using an equivalent circuit showed the dominant influence of grain boundaries. Low hysteresis (3.6 and 2.99%) was obtained in the 40–90% humidity range at room temperature (25 °C) for pseudobrookite sintered at 950 and 1150 °C. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.This is the peer-reviewed version of the article: Nikolic, M.V., Lukovic, M.D., Vasiljevic, Z.Z., Labus, N.J., Aleksic, O.S., 2018. Humidity sensing potential of Fe2TiO5—pseudobrookite. Journal of Materials Science: Materials in Electronics 29, 9227–9238. [https://doi.org/10.1007/s10854-018-8951-1

Microstructure development and electrical properties of NiO doped alpha-Fe2O3

Poster presented at the 4th Serbian Congress for Microscopy, Belgrade, Serbia, 2010, October 11-12, 201

Intrinsic resistivity of sintered nickel manganite vs. powder activation time and density

Poster presented at the conference Fizika i tehnologija materijala (Physics and Technology of Materials), FITEM '07, Čačak, Serbia, August 6-8, 2007.Paper: [https://hdl.handle.net/21.15107/rcub_dais_208]Final results were published in the article [http://dx.doi.org/10.2298/SOS0801027S

Nanostructured Fe2O3/TiO2 thick films prepared by screen printing

Nanostructured single layered (pure TiO2 , pure α-Fe2O3 and mixed Fe2O3 /TiO2 with two different oxide ratios, 2 : 3 and 3 : 2) and double layered (TiO2 layer over a Fe2O3 layer) thick films have been fabricated by screen printing technology on a glass substrate. The pastes used for film preparation were obtained by adding an organic vehicle to the oxide powders together with a small percentage of binding glass frit. Samples were dried up to 100 °C and sintered at 650 °C/60 minutes. Structural, morphological and optical studies have been carried out using XRD, SEM analyses and UV/Vis spectroscopy. The prepared pure and mixed Fe2O3 /TiO2 thick films had a homogenous nanostructure without secondary phases. Indirect band gaps were determined from the measured transmission spectra and the obtained values are in the range of literature data. [Projekat Ministarstva nauke Republike Srbije, br. III45007

Changes of Structural, Optical and Electrical Properties of Nickel-Manganite Ceramics Induced by Additional Mechanical Activation

Poster presented at the 10th International Conference and Exhibition of the European Ceramic Society, Berlin, June 17-21, 200