Influence of CuO additions and sintering temperatures on the microwave dielectric properties of CaLa 4Ti 5O 17 ceramics

Abstract

In this study, the microwave dielectric properties of CaLa 4Ti 5O 17 ceramics have been investigated. CuO was selected as liquid sintering aids to lower the sintering temperature of CaLa 4Ti 5O 17. It is found that the X-ray diffraction pattern exhibited no phase difference with 0.5 wt.% CuO additive at different sintering temperatures. A maximum value of dielectric constant of 57, a maximum value of quality factor multiplies resonant frequency ( Q × f) of 9000 GHz, and a temperature coefficient of resonant frequency ( τ f = −10 ppm/°C) can be obtained with 0.5 wt.% CuO additive and sintered at 1450 °C for 4 h. A near-zero temperature coefficient of resonant frequency ( τ f = −4.9 ppm/°C) was measured for CaLa 4Ti 5O 17 ceramics with 1.0 wt.% CuO sintered at 1350 °C for 4 h.