Study of Temperature Dependent Dialectical Properties of One System Ceramics using BNT-BZ

Aloke Verma

Abstract: In this paper, Study of temperature dependent dialectical properties of one system ceramics like BNT-BZ. Lead-free BNT-BZ ceramics were successfully prepared using the conventional mixed-oxide method. The samples were sintered for 2 hrs at temperatures lower than 1, 000C. The density of the BNT-BZ samples was at least 95 % of the theoretical values. The scanning electron microscopy micrographs showed that small grains were embedded between large grains, causing a relatively wide grain size distribution. The density and grain size increased with increasing Zr concentration. A peak shift in X-ray diffraction patterns as well as the disappearance of several hkl reflections indicated some significant crystal-structure changes in these materials. Preliminary crystal-structure analysis indicated the existence of phase transition from a rhombohedral to an orthorhombic structure. The dielectric and ferroelectric properties were also found to correlate well with the observed phase transition.

Keywords: ceramics, X-ray diffraction, dielectric properties, ferroelectricity