Formation mechanism and characteristics of lanthanum-doped BaTiO3 powders and ceramics prepared by the sol-gel process

摘要

Pure and lanthanum-doped barium titanate nanopowders described by two different formulae, as Ba1-xLaxTiO3, for lower La concentrations (0 <= x <= 0.005) and Ba1-xLaxTi1-xO3 for higher La concentration (x = 0.025) were prepared by an alkoxide sol-gel method. Single phase compositions were obtained after annealing at 900 degrees C for 2 h, in air. The increase of the lanthanum content causes structural and morphological changes in the oxide powders, including the evolution of the unit cell from tetragonal toward a cubic symmetry, the particle size decrease and a higher aggregation tendency.