Temperature-stable dielectric ceramics with nominal composition of Ca6Ti2Ta8O30

The dielectric ceramics with nominal composition of Ca6Ti2Ta8O30 were synthesized and characterized. The cubic CaTa2O6 major phase combined with minor amount of CaTiO3 were formed in the present ceramics, and this differed from the similar compositions of Ba6Ti2Ta8O30 and Sr6Ti2Ta8O30, which had the filled tungsten bronze structure. The present ceramics indicated a high dielectric constant of 85–86 with a small temperature coefficient of dielectric constant of +24–29 ppm/°C together with a dielectric loss of 0.0056–0.0060 (at 1 MHz). The dielectric constant was almost a constant, while the dielectric loss and temperature coefficient of dielectric constant were sensitive to the sintering conditions. The present ceramics might be promising in temperature compensated capacitor applications.