Effects of La Content on the Properties of Ba_(1-x)La_xTiO_3 Powders Prepared by Spray Pyrolysis

摘要

Nano-sized Ba_(1-x)La_xTiO_3 (0 <= x <= 0.03) powders were prepared by ultrasonic spray pyrolysis from the spray solution with citric acid. The mean sizes of the primary particles decreased from 110 nm to 59 nm when the x of the Ba_(1-x)La_xTiO_3 powders was changed from 0 to 0.03. The BET surface areas of the powders changed from 9.1 m~2/g to 16.9 m /g. The pure BaTiO_3 and La-doped BaTiO_3 powders had both tetragonal and cubic crystal structures. The average grain size of the sintered BaTiO_3 specimen was 2.8 mum, while those of the La-doped BaTiO_3 pellets ranged from 1.04 mum to 0.68 mum according to the doping concentrations of La. The dielectric constant of Ba_(1-x)La_xTiO_3 (0.01 <= x <= 0.03) pellets ranged from 2500 to 3855 when sintered at 1280 deg C.