Enhancement microwave dielectric properties of La(Mg0.5Sn0.5)O3 ceramics by substituting La3+ with Sm3+

The microwave dielectric properties of La1−xSmx(Mg0.5Sn0.5)O3 ceramics were examined with a view to their exploitation for mobile communication. The La1−xSmx(Mg0.5Sn0.5)O3 ceramics were prepared by the conventional solid-state method with various sintering temperatures. The X-ray diffraction patterns of the La0.97Sm0.03(Mg0.5Sn0.5)O3 ceramics revealed no significant variation of phase with sintering temperatures. Apparent density of 6.59 g/cm3, dielectric constant (εr) of 19.9, quality factor (Q×f) of 70,200 GHz, and temperature coefficient of resonant frequency (τf) of −77 ppm/°C were obtained for La0.97Sm0.03(Mg0.5Sn0.5)O3 ceramics that were sintered at 1500 °C for 4 h. The dielectric constant, and τf of La0.97Sm0.03(Mg0.5Sn0.5)O3 ceramics were almost independent with the sintering temperature as the sintering temperature varied from 1450 to 1600 °C.

► La0.97Sm0.03(Mg0.5Sn0.5)O3 sintered at 1500 °C for 4 h had a εr of 19.9.
► The εr was affected by the density, ionic polarization, and amount of second phase.
► La0.97Sm0.03(Mg0.5Sn0.5)O3 sintered at 1500 °C for 4 h had a Q×f of 70,200 GHz.
► The Q×f depended on the density, grain size, and amount of second phase.
► La0.97Sm0.03(Mg0.5Sn0.5)O3 provides a wide process window.