Microwave Dielectric Properties of ((A{sup}(2+)){sub}(1/3)(B{sup}(5+)){sub}(2/3)){sub}0.5Ti{sub}0.5O{sub}2 (A{sup}(2+)=Zn, Mg, B{sup}(5+)=Nb, Ta) Ceramics

摘要

Dielectric properties of ((A{sup}(2+)){sub}(1/3)(B{sup}(5+)){sub}(2/3)){sub}0.5 Ti{sub}0.5O{sub}2 (A{sup}(2+)=Zn, Mg, B{sup}(5+)=Nb, Ta) ceramics were investigated at microwave frequencies. Dielectric properties were strongly dependent on the structural characteristics and cooling rate. The specimens with Nb{sup}(5+) showed larger dielectric constant (K) than those with Ta{sup}(5+) due to the decrease of bond valence. Quality factor (Qf) of the specimens was dependent on the reduction of Ti{sup}(4+) ion as well as microstructure. Temperature coefficients of the resonant frequencies (TCF) of the specimens with Nb{sup}(5+) were larger than those with Ta{sup}(5+). These results could be attributed to the changes of oxygen octahedral distortion.