Effect of Bi2O3 additives on sintering and microwave dielectric behavior of La(Mg0.5Ti0.5)O3 ceramics

Bi2O3 was selected as liquid phase sintering aid to lower the sintering temperature of La(Mg0.5Ti0.5)O3 ceramics. The sintering temperature of La(Mg0.5Ti0.5)O3 ceramics is generally high, about 1600 °C. However, the sintering temperature was significantly lowered about 275 °C from 1600 °C to 1325 °C by incorporating in 15 mol% Bi2O3 and revealed the optimum microwave dielectric properties of dielectric constant (ɛr) value of 40.1, a quality factor (Q × f) value of 60,231 GHz, and the temperature coefficient (τf) value of 70.1 ppm/°C. During all addition ranges, the relative dielectric constants (ɛr) were different and ranged from 32.0 to 41.9, the quality factors (Q × f) were distributed in the range of 928–60,231 GHz, and the temperature coefficient (τf) varies from 0.3 ppm/°C to 70.3 ppm/°C. Noticeably, a nearly zero τf can be found for doping 5 mol% Bi2O3 sintering at 1325 °C. It implies that nearly zero τf can be achieved by appropriately adjusting the amount of Bi2O3 additions and sintering temperature for La(Mg0.5Ti0.5)O3 ceramics.