RAMAN STUDY OF FERROELECTRIC BISMUTH LAYER-OXIDE ABi4Ti4O15 PREPARED BY THE MECHANOCHEMICAL SYNTHESIS

Abstract

Ferroelectric materials have innumerable properties related totheir spontaneus polarization, for instance. pyre- and piezoelectricity, which are used for various sensors and actuators il 1. BaBi4Ti4O12 (BBT) is an r : 4 member of the Bi-layer structured ferroelecrtric oxide family (Auriviltius phase) [2]. Bi-layered structure ferroelectric material - bismuth titanate, Bi+Ti:Orz (BIT) and barium-bismuth titanate, BaBi+Ti+Ors (BBT) ceramic powders were prepared by mechanical synthesis possess. BaBi+TiaOrs was prepared from stoichometric quantities of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Barium titanate, BaTiOt has been synthesised from mixture of BaO and TiGz and bismuth titanate, Bi+TirOr: was prepared starting from BiuO: and TiOz, comercialy available. The reaction mechanism of BBT and the preparation and characteristics of BBT ceramic powders u,ere studied using X-ray diffraction (XRD) and IR spectroscopy The phonon modes have been studied by Rarran spectroscopy. The Bi-layered perovskite structure of BBT cerantic fbrrns at ll00 "C. Microstructure of Bi+Ti:Or1 is in accordiance with the vierv that Bi,rTilOr:exhibits plate-like grains with thr average grain size increasing u,,ith the sintering temperature. lt is eviclent that Ba2- aclition leads to the change in the microstructure development, particularly in the change of the average grain size an; homogeneity of the grains of BaBi4Ti4O12.