Effect of La substitution on the structural and dielectric properties of BaZr<inf>0.1</inf>Ti<inf>0.9</inf>O<inf>3</inf> ceramics

Lanthanum substituted BaZr0.1Ti0.9O3 (Ba1-3x/2LaxZr0.1Ti0.9O3 and x = 0.01-0.05) ceramic powders were prepared through a solid state mixed oxide technique. Phase formation was confirmed using X-ray diffraction studies. It was also observed that when Ba/Ti < 1, La preferentially occupied the Ba site. The microstructure investigation using SEM showed that La substitution modified the grain size of the BaZr0.1Ti0.9O3 ceramic significantly, from about 100 μm to ∼5 μm. Variation in the La content (from 1 mol% to 5 mol%) has negligible influence on the grain size and morphology of the ceramic. The increase in the La content decreased the Curie temperature of the BaZr0.1Ti0.9O3 ceramic. The dielectric maximum was observed at 2 mol% of La substitution and with further increase in La content the phase transition was found to be broad. The dielectric constant has improved significantly compared to the BaZr0.1Ti0.9O3 ceramic material. © 2009 Elsevier B.V. All rights reserved.