Dielectric properties of nano-sized Ba0.7Sr0.3TiO3 powders prepared by spray pyrolysis

Nano-sized Ba0.7Sr0.3TiO3 powders are prepared by post-treatment of the precursor powders with hollow and thin wall structure at temperatures between 900 and 1100 °C. Ethylenediaminetetraacetic acid and citric acid improve the hollowness of the precursor powders prepared by spray pyrolysis. The mean sizes of the powders post-treated at temperatures of 900, 1000 and 1100 °C are 42, 51 and 66 nm, respectively. The densities of the Ba0.7Sr0.3TiO3 pellets obtained from the powders post-treated at 900, 1000 and 1100 °C are each 5.36, 5.55 and 5.38 g cm−3 at a sintering temperature of 1300 °C. The pellet obtained from the powders post-treated at 1000 °C has higher maximum dielectric constant than those obtained from the powders post-treated at 900 and 1100 °C.