High temperature dielectric properties of calcium zirconate

Abstract The electrical properties of dense, high purity CaZrO ₃ discs, sintered at 1380°C with and without added ZrO ₂ , were investigated up to 950°C. Dielectric constant, loss tangent, and electrical conductivity were measured from 25 to 725°C, and the real and imaginary impedances were measured between 800 and 950°C by impedance spectroscopy techniques. Dielectric constant increased by 8% above 300°C and loss tangent increased from .1% at 25°C to ∼2% above 300°C. Activation energy of electrical conductivity determined between 300°C and 950°C by alternative current (AC) and direct current (DC) measurements. These results indicate that CaZrO ₃ could be a useful dielectric material for capacitor applications up to 500°C. A reported decrease in conductivity due to addition of excess ZrO ₂ into stoichiometric CaZrO ₃ could not be confirmed.