The microwave dielectric properties and the microstructures of LaAlO3 ceramics with B2O3 additions (0.25-1 wt%) prepared with conventional solid-state route have been investigated. Doping with B2O3 (up to 0.5 wt%) can effectively promote the densification of LaAlO3 ceramics. It is found that LaAlO3 ceramics can be sintered at 1400°C due to the liquid phase effect of B2O3 addition. The Q × f value as well as the dielectric constant decreases at higher B2O3 doping level (1 wt%) due to the increase of boundary phases. At 1460°C, LaAlO3 ceramics with 0.5 wt% B2O3 addition possesses a dielectric constant (εr) of 22.9, a Q × f value of 44700 (at 9 GHz) and a temperature coefficients of resonant frequency (τf) of -36 ppm/°C. The B2O3-doped LaAlO3 ceramics can find applications in microwave devices requiring low sintering temperature.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering