The Effect of Firing Temperatures on Phase Evolution, Microstructure, and Electrical Properties of Ba(Zr0.05Ti0.95)O3 Ceramics Prepared via Combustion Technique

Abstract

In this work, the effects of calcination temperature (900 ºC – 1200 ºC for 2 h – 6 h) and sintering temperature (1350 ºC – 1550 ºC for 2 h) on phase evolution, microstructure and electrical properties of barium zirconate titanate Ba(Zr_0.05Ti_0.95)O₃ (BZT) ceramics fabricated through the combustion technique were investigated. Glycine was used as fuel to reduce the reaction temperature. It was found that a single perovskite phase of BZT powders was observed from the sample calcined at 925 ºC for 6 h, which was lower than the solid state reaction technique ~275 ºC. The purity phase of an orthorhombic structure was observed in all ceramic samples. The average particle size (190 nm – 420 nm) and the average grain size (2.9 mm – 41.4 mm) increased with increased firing temperatures. The maximum theoretical density of ~96.8 % was obtained from the sample sintered at 1450 ºC for 2 h. The dielectric constant at room temperature (T_r) and the dielectric constant at Curie temperature (T_c) increased with increased sintering temperatures up to 1450 ºC and decreased thereafter. The dielectric properties corresponded to the obtained densities. The remnant polarization (P_r) of the BZT ceramic (using the coercive electric field of 20 kV/cm) increased with increasing sintering temperature.

DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6436