Structural Study of (1-x) (Bi0.5Na0.5) TiO3 -xLiNbO3 Solid-Ceramics

Abstract

Bismuth sodium titante Lithium Niobate (1-x)(Bi_0.5Na_0.5)TiO₃-xLiNbO₃where (x=0.01,0.02,0.03)[BNTLN] which is a lead free antimony are prepared by conventional method of solid state reaction method. BNTLN samples are selected such that density about 95% of theoretical values. The phase formation was confirmed by X-ray diffraction (XRD). Bi_0.5Na_0.5TiO₃ was investigated by XRD and Raman spectroscopy for phase formation and local structure. The density and grain size depend upon Li,Nb concentration and found propsanal to LiNbO₃ concentration. In X-ray diffraction patterns the peak decreases with increase in LiNbO₃. In Preliminary crystal-structure analysis shows the existence of phase transition from rhombhedral to a hexagonal structure.

A splitting of (TO3) mode at x=0.03. With increase in x change in peak position, width and intensity respectively has been noticed in Raman spectrum with increase in LiNbO₃ concentration piezoelectric properties increase and found optimum at x=0.03.This optimum value is due to co-existence of two ferroelectric phases. Thus it is conducted that morphotropic phase boundary in (1-x )(Bi_0.5Na_0.5)TiO₃-xLiNbO₃  lies for composition x=0.03.