Characteristics of BaO–B2O3–SiO2 nano glass powders prepared by flame spray pyrolysis as the sintering agent of BaTiO3 ceramics

Nanosized BaO–B2O3–SiO2 glass powders are directly prepared by flame spray pyrolysis. The mean size of the BaO–B2O3–SiO2 glass powders with amorphous phase and spherical shape is 30 nm. The effects of glass powders on the sintering characteristics of the BaTiO3 pellet formed from the nanosized BaTiO3 powders are investigated. The mean size and BET surface area of the BaTiO3 powders prepared by spray pyrolysis are 110 nm and 9.1 m2/g. The BaTiO3 pellet with glass additive has large grain size with several microns, dense structure and pure tetragonal crystal structure at a sintering temperature of 1000 °C. The XRD pattern of the pellet has distinct split of (2 0 0) and (0 0 2) peaks at 2θ ≈ 44.95°. The dielectric constant of the pellet without glass additive is 2180. However, the dielectric constants of the pellets with 1, 3, 5 and 7 wt% glass additive with respect to BaTiO3 are 2496, 2514, 2700 and 2225, respectively.

► Nanosized BaO–B2O3–SiO2 glass powders with spherical shape are directly prepared by flame spray pyrolysis. ► Nanosized glass powders improved the sintering characteristics of the BaTiO3 pellet at a low sintering temperature of 1000 °C. ► The dielectric constants of the BaTiO3 pellets with and without glass additive are 2180 and 2700.