Optimization of sintering temperature for dielectric studies of La doped BZT ceramics

In this work, we have reported optimization of sintering temperature for dielectric studies of Lanthanum (La3+) doped BZT ceramics. The sample Ba0.99La0.01Zr0.10Ti0.90O3 has been prepared by conventional solid-state reaction route with calcination at 1000 °C and 1100 °C. Samples calcined at both the temperatures have been sintered at three different temperatures 1125 °C, 1225 °C and 1325 °C. The as-synthesized samples have been characterized by X-ray diffraction for structural studies and scanning electron microscopy to confirm the surface morphology. XRD patterns of Ba0.99La0.01Zr0.10Ti0.90O3 calcined at 1100 °C show single crystalline phase with no impurity at 1325 °C. It has been observed that sintering temperature strongly influences the crystal structure and the dielectric properties of the prepared ceramic samples. The sharp and intense peaks in the XRD pattern of sample calcinated at 1100 °C and sintered at 1325 °C represents the formation of single-phase cubic perovskite structure. This indicates the incorporation of La3+ ions into the lattice of barium zirconium titanate. High dielectric constant has been observed at low frequency. Phase structure, variation of dielectric constant, loss and a.c conductivity with frequency at room temperature of Ba0.99La0.01Zr0.10Ti0.90O3 ceramic sample have been investigated in this paper.