Effects of glass additions on microstructure and microwave dielectric properties of La4Ti9O24 ceramics

Two commercially available glasses, PbO-B2O3-SiO2 (GA-9) and ZnO-B2O3-SiO2 (GP-032), were used to improve the sintering property of La4Ti9O24 ceramics. Above 20 vol.% of respective GA-9/GP-032 addition, La4Ti9O24 ceramics with ∼95% of the theoretical density were obtained at a relatively low temperature of ∼1000 °C, compared to the sintering temperature, ∼1350 °C, for preparing pure La4Ti9O24 bulks with a similar density. The interaction between GA-9 and La4Ti9O24 results in the formation of a secondary phase La2/3TiO3. Further investigations indicated that La2/3TiO3 has a strong influence on the microwave dielectric property of La4Ti9O24 ceramics with GA-9 addition.