Influence of ZrO₂ Addition on the Structure and Dielectric Properties of BaTiO₃ Ceramics

Ba(Ti_{1-x}Zr_{x})O₃ (x=0÷0.3) ceramics were prepared by the standard solid state reaction method and were sintered at 1450°C for 4 h. The structural and dielectric properties of the samples were studied. The phases formed in the ZrO₂ doped BaTiO₃ were tetragonal and of cubic symmetry. Increase in ZrO₂ content in the BaTiO₃ caused to increase of the lattice parameter and crystallite size of the perovskite structure. The evolution of the Raman spectra was studied for various compositions and the spectroscopic signature of the corresponding phase was determined. The scanning electron microscope was used to investigate the microstructure and surface morphology of the sintered samples. Scanning electron microscope observations revealed enhanced microstructural uniformity and retarded grain growth with increase of ZrO₂ content. Dielectric characteristics of ZrO₂ doped barium titanate were studied using a Hioki 3532-50 LCR meter in the frequency range of 1 kHz-1 MHz. It is found that the dielectric constant (ε_{r}) increases while the dielectric loss (tan δ) decreases with increase in zirconium oxide content (x<0.3).