Faculty of Technology, University of Novi Sad Bul. cara Lazara 1, 21000 Novi Sad, Serbia
Abstract
Bismuth ferrite (BiFeO3) is one of the very few materials possessing ordered both
electrical dipoles and magnetic moments in very wide range of temperatures. That gives
it tremendous opportunities for research and application.
BiFeO3 precursor powders were prepared by auto-combustion and soft chemical
synthesis methods using different organic compounds as fuels and complexing agents.
They were calcined at 600 °C for 2 h, grinded, pressed and sintered at 800 °C for 1 h
with quenching. XRD and SEM confirmed formation of very pure BiFeO3 perovskite
phase, but problem with low density, which is characteristic for BiFeO3 ceramics, still
remained. It doesn’t affect magnetic properties, but has strong influence on electrical
and, through them, on multiferroic properties. To define actual, intrinsic properties of
material, it is very important to obtain ceramics with densities close to theoretical. For
this reason, many treatments were tried in order to raise samples’ densities: powder
milling and homogenization, ultrasound, different pressures, various thermal treatments.
Powders and ceramic samples were then characterized (particle size analysis, XRD,
SEM). The densities of sintered BiFeO3 samples were measured. All the treatments had
impact on ceramics density, but some also introduced secondary phases
