Preparation and Characterization of PrAlO_3-Doped 0.95MgTiO_3-0.05CaTiO_3 Microwave Dielectric Ceramics

摘要

Microwave dielectric ceramics with a nominal composition of 0.95MgTiO_3-0.05CaTiO_3-xPrAlO_3 (x = 0 ～ 0.015) were prepared by conventional solid-state sintering. The phase composition, microstructure and dielectric properties were characterized byX-ray diffractometer, scanning electron microscope and vector network analyzer, respectively. A two-phase system with major MgTiO_3 phase andminor CaTiO_3 phase was detected. With increasing content of PrA103, the grain size of the obtained ceramics decreased; the dielectric constant and quality factor increased first and then decreased. The temperature coefficient of resonant frequency decreased after PrAlO_3 was doped, but with morePrAlO_3dopedit will increase. The obtained 0.95MgTiO_3-0.05CaTiO_3 ceramic doped by PrAlO_3 with x=0.0075 presented the best performance with ε_r= 19.04, Q·f=42400 GHz and τ_f=-19.40 ppm/°C