Structure and dielectric characterization of xNd(Mg1/2Ti1/2)O3–(1−x)Ca0.6La0.8/3TiO3 in the microwave frequency range

Abstract The crystal structures, phase compositions and the microwave dielectric properties of the x La(Mg 1/2 Ti 1/2 )O 3 –(1 − x )Ca 0.8 Sr 0.2 TiO 3 composites prepared by the conventional solid state route have been investigated. The formation of solid solution is confirmed by the XRD patterns. Doping with B 2 O 3 (0.5 wt.%) can effectively promote the densification and the dielectric properties of x Nd(Mg 1/2 Ti 1/2 )O 3 –(1 − x )Ca 0.6 La 0.8/3 TiO 3 ceramics. It is found that x Nd(Mg 1/2 Ti 1/2 )O 3 –(1 − x )Ca 0.6 La 0.8/3 TiO 3 ceramics can be sintered at 1375 °C, due to the liquid phase effect of B 2 O 3 addition observed by Scanning Electronic Microscopy. At 1375 °C, 0.4Nd(Mg 1/2 Ti 1/2 )O 3 –0.6Ca 0.6 La 0.8/3 TiO 3 ceramics with 1 wt.% B 2 O 3 addition possesses a dielectric constant ( ɛ r ) of 49, a Q × f value of 13,000 (at 8 GHz) and a temperature coefficients of resonant frequency ( τ f ) of 1 ppm/°C. As the content of Nd(Mg 1/2 Ti 1/2 )O 3 increases, the highest Q × f value of 20,000 GHz for x = 0.9 is achieved at the sintering temperature 1400 °C.