Ni ion diffusion in barium titanate perovskite

Abstract

The diffusion characteristics of Ni ion were evaluated in non-doped, Ho-doped polycrystalline and single-crystal barium titanate perovskite (BaTiO3) using a secondary ion mass spectrometry (SIMS). The volume diffusion coefficients of Ni (1100≤T≤1400°C) were described as follows; non-doped BaTiO3: Dv[cm2/s] = 1.4 × 10-6 exp(-241.9[kJ/mol]/RT), Ho-doped BaTiO3: Dv[cm2/s] = 4.4 × 10-6 exp(-227.7[kJ/mol]/RT), single-crystal BaTiO3: Dv[cm2/s] = 6.7 × 10 exp(-437.2[kJ/mol]/RT). The difference of diffusion coefficients could be explained through of the defect chemistry. The grain boundary diffusion was also estimated by using the same method. It was indicated that grain boundary diffusion was influenced by the microstructure.