Effects of copper-based compounds addition on the microstructures and dielectric properties of barium titanate ceramics having ultra-fine grains

The influences of the Cu-addition on the microstructures and dielectric pro perties of BaTiO3 ceramics were investigated, when the nano-crystalline BaT iO3 powder having the average particle size smaller than 60 nm was used as starting materials. Grains smaller than 350 nm were uniformly distributed w hen the [Cu] or the sintering temperature was low, but abnormal grain growt h occurred as the sintering temperature or the [Cu] increased. As the area fraction of the abnormally grown grains decreased, the dielectric transitio n at T-C became more diffuse. The results were attributed to the internal s tress model.