Structure and Properties of Barium Bismuth Titanate Prepared by Mechanochemical Synthesis

Abstract

Recently there has been renewed interest in the properties of the Aurivillius phases as temperature-stable ferropiezoelectrics [1 ]. Several bismuth-layered crystal structures and their properties have been investigated in detail [2]. However, a lot of aspects of the preparation and properties of barium bismuth titanate remain unexplored, whereas being promising candidate for memory applications. In present work barium bismuth titanate (BaBi4Ti4Ors- BBT) was prepared from stoichiometric quantities of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Barium titanate (BaTiO3-BT) has been synthesised from mixture of BaO and TiO2 and bismuth titanate (Bi4Ti3Or2-BIT) was prepared starling from Bi2O3 and TiO2, commercially available. \4echanochemical synthesis was performed in air atmosphere in a planetary ball mill, for BT during 60 min and for BIT during 360 min. Milling conditions were: zirconium oxide jars and zirconium oxide balls, ball-to-powder weight ration 20:7 and determined basic disc and disc with jars rotation speed. The powder mixture of BT and BIT was homogenized for 60 min. BaEli4Ti4ols ceramics were sintered at 1100'C for 2, 4 and 12 hours without pre-calcination step. The heating rate was 1OoC/min. The formation of phase and crystal structure of BaTiO3, Bi4Ti3O12 and BaBiaTiaOl5 were approved by XRD analysis. The morphology of obtained powders and microstructure were examined by SEM method. The electrical properties of sintered samples were carried out.