Dielectric properties of [(Pb0.2Ca0.8)1−xSrx](Ca1/3Nb2/3)O3 ceramics at microwave frequencies

Microwave dielectric properties of the [(Pb0.2Ca0.8)1−xSrx](Ca1/3Nb2/3)O3 (PCSCN) have been investigated as a function of Sr2+ content (0.05≤x≤0.2). A perovskite single phase with the CaTiO3-type structure was obtained throughout the entire composition range. Dielectric constant (K) increased with increase of Sr2+ content, however, the quality factor (Qf) was decreased. The increase of dielectric constant (K) could be attributed to the increase of ionic polarizability and the decrease of A-site bond valence of the specimens. Temperature coefficient of resonant frequency (TCF) increased with Sr2+ content from −22.26 to −9.15 ppm/°C, which could be explained by the change of bond valence and tolerance factor (t) of the perovskite structure.