Papers by Author: Marija Maletin

Abstract: Yttrium- and indium-doped zinc-ferrite nanoparticles were prepared by a coprecipitation method. The influence of doping level on the structure and the conductivity of the samples obtained was investigated. It was found that Y-doped zinc-ferrite nanoparticles, with a single spinel phase and a size of a few nanometers, are formed in the whole range of yttrium concentration. However, In-doped zinc-ferrite nanoparticles were formed for all investigated indium cooncentrations, but only the samples InxZn1-xFe2O4 with x.≤ 0.15 are single-phase (for x ≥ 0.20 a second phase - cubic In(OH)3, is formed). The decrease and increase of the electrical conductivity with yttrium and indium doping respectively are explained by taking into consideration the different role of these ions in the spinel structure and the electron hopping mechanism.

Abstract: Advances in nanoscale electronics require superior ceramic powders, preferable prepared with techniques for the direct synthesis of crystalline nanoparticles. Zinc ferrite (ZnFe2O4) nanopowders were prepared by co-precipitation method, from nitrate precursors. Crystalline powders having the single-phase cubic spinel structure were directly synthesized at temperature ≥80°C in the presence of NaOH. The obtained powders are agglomerated with ultra-fine crystallites having the average crystallite size about 3-4 nm.