Characterization of Pb -free “x [Ba (Zr0.2Ti0.8) O3] - (1- x) [(Ba0.7Ca0.3) TiO3]”Ceramics Synthesized by Solid State Reaction Route

Abstract

In the present project, x [Ba (Zr0.2Ti0.8) O3] – (1-x) [(Ba0.7Ca0.3) TiO3] (abbreviated as xBZT- (1-x) BCT) (where x= 0.4, 0.5, 0.6) lead-free ceramics were synthesized by conventional solid state route. XRD analysis of calcined sample shows formation of perovskite phase. The BZT- BCT ceramic samples were calcined & sintered at lower temperatures 12000C and 13000C, respectively which was lower compared to the previous reported literature. The average crystallite size calculated from XRD was 40 nm for 50BZT-50BCT ceramic. Dielectric measurements were carried out for the compositions over the frequency range 1Hz -1MHz and temperature range from 280C to 2200C. Each sample showed a maximum dielectric constant at the Curie temperature (TC). With increase in the value of ‘x’ from 0.4 to 0.6 the composition had shown decrease in the Curie temperature values which were 830C, 770C and 720C respectively. The dielectric and piezoelectric properties of our sintered samples are comparable to those of conventionally prepared BZT-BCT ceramics reported earlier. These ceramics are potential candidates for the lead-free piezoelectric applications.