The correlation between τɛ and the tolerance factor in (Sr, Ca) (Ti, Zr)O3 microwave dielectric ceramics

Abstract
Microwave dielectric properties and the relationship between the temperature coefficient of the dielectric constant (τ ɛ) and the tolerance factor were investigated in (Sr0.2Ca0.8) (Ti1–xZrx)O3 ceramics. The τɛ increased linearly as the tolerance factor decreased from 0.984 to 0.929 in the whole composition range of the (Sr0.2Ca0.8) (Ti1–xZrx)O3 solid solution. At the composition of (Sr0.2Ca0.8) (Ti0.04Zr0.96)O3, the dielectric constant was 34 and Q · f was 10,938 GHz and the temperature coefficient of the resonance frequency (τɛ) was supposed to be near zero.