Effect of Pb_0.8La _0.2Ti_0.95O₃ Doping on the Electrical and Dielectric Properties of CCTO Compound Synthesized by Hybrid Method

Abstract

In this work we studied the effect of the addition PL0.2T on the structural, electrical properties of the CCTO ceramic of (1-x) CaCu3Ti4O12 - x Pb0.8 La0.2Ti0.95O3 ((1-x) CCTO-x PL0.2T) with x=0.0; 0.2; 0.3; 0.4; 0.7and 1.0. The composites materials are prepared by hybrid method (solid-sol-gel) and sintered at 1000 °C for 4H. The X-Ray diffraction results reveal that the PL0.2T crystallizes in pure pseudo-cubic phase with Pm3m space group, while the CCTO show a cubic phase structure with space group Im-3. The composites samples of (1-x) CCTO-x PL0.2T indicate the coexistence of two cubic and pseudo-cubic phases. The SEM image indicate a change in grain shape and decrease of average grain size with increasing of PL0.2T content. The dielectric measurements as a function of temperature, show two anomalies which exhibit a relaxation phenomenon for x=0.2 and x=0.7 and a decrease dielectric constant value, it’s can be explained by the phase transition phenomenon of PL0.2T. The Cole-Cole diagram for all samples showed existence of two semi-arcs attributed to the grains and grains boundary, and it is found that the Rg values are smaller than the Rgb. The electrical properties give evidence on the formation of interior, barrier layer capacity (IBLC).