Effects of co-precipitation method on microwave dielectric properties of 0.7CaTiO₃-0.3SmAlO₃ceramics

Abstract

The effects of co-precipitation method on densification, microstructure, phase composition and dielectric properties of 0.7CaTiO 3 -0.3SmAlO 3 ceramics (CTSA) have been studied. Compared with the traditional solid-phase method, the co-precipitation method effectively reduced the calcining temperature of CaTiO 3 powders and SmAlO 3 powders from 1250 to 900°C and reduced the sintering temperature of CTSA ceramics from 1470 to 1380°C. The sintering and dielectric properties were improved. In particular, the Q×f value was found to increase from 47 056 to 51 507 GHz and the τ f reduced from +8.2 to +6.3 ppm°C. The CTSA ceramics, which were prepared by co-precipitation method sintered at 1380°C for 3 h, possessed good and reasonable microwave dielectric properties: ε r =44.85, Q×f=51 507 GHz ( f=6.45 GHz), τ f =+6.3 ppm°C.