Structure and Dielectric Behavior of La-doped BaTiO3 Ceramics

BaTiO(3) ceramics doped with 1, 2, 3 and 4 mol% La were prepared by sol-gel method. The effects of La doping on structure and dielectric characteristics of Ba(1-x)La(x)TiO(3) were investigated. The results show that: All the powders calcined at 800 degrees C were found to be perovskite structure with cubic phase. Ba(1-x)La(x)TiO(3) were sintered at 1300 degrees C, phase transition behavior appeared from tetragonal phase to cubic phase with increasing La-doping level. As the doping concentration increases, the grain growth of the Ba(1-x)La(x)TiO(3) ceramics was controlled efficiently and Curie point shifted to lower temperature. The grain size decreased from 20 mu m with 0 mol% La doped to 0.5 mu m with 4 mol% La doped. The Curie point shift rate was 22 degrees C/ mol% with increasing La content. The dielectric constant of La doped Ba(1-x)La(x)TiO(3) ceramics increased with increasing La content and a maximum value of 8900 was attained with 4 mol% La doped.