Preparation and Characterization of PrAlO3-Doped 0.95MgTiO3-0.05CaTiO3 Microwave Dielectric Ceramics

Abstract

Microwave dielectric ceramics with a nominal composition of 0.95MgTiO3-0.05CaTiO3-xPrAlO3(x=0-0.015) were prepared by conventional solid-state sintering. The phase composition, microstructure and dielectric properties were characterized by X-ray diffractometer, scanning electron microscope and vector network analyzer, respectively. A two-phase system with major MgTiO3phase and minor CaTiO3phase was detected. With increasing content of PrAlO3, 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 PrAlO3was doped, but with more PrAlO3doped it will increase. The obtained 0.95MgTiO3-0.05CaTiO3ceramic doped by PrAlO3with x=0.0075 presented the best performance with εr=19.04, Q·f=42400 GHz and τf=-19.40 ppm/°C.