Diffuse phase transition in sol–gel-prepared modified Pb(La,Cs)(Zr,Ti)O 3

Abstract

In this paper, we report the development of Cs-modified PbLa(Zr,Ti)O 3 near the morphotropic phase boundary (MPB) using a sol–gel technique and present results of structural, dielectric and resistivity properties. The powder was prepared by a sol–gel process using lead acetate, lanthanum acetate, cesium chloride and zirconium nitrate. X-ray structural analyses of these PLCZT compounds suggested the formation of single-phase compounds having a tetragonal structure at relatively low temperature around 820°C for 4 h. The sintering temperature of these compounds was 1030°C for 2 h, which was comparatively lower than the powders made by the conventional methods. The ferroelectric phase transition of PLCZT materials was studied using dielectric measurements. The transition was found diffuse in type, and the transition temperature shifted towards the higher-temperature side with increase in Cs ion concentration. Analyses of diffusivity ( γ) of these compounds showed values between 1 and 2, which suggests the variation/degree of disordering in the systems. The DC electrical resistivity increases with increase in Cs ion concentration.