Oxygen diffusion along the short-circuit paths in bicrystal SrTiO3

Abstract

Oxygen diffusion in bicrystal SrTiO3 was investigated with the aid of resistive anode encoder of secondary-ion mass spectrometry. The diffusion profiles of 18O on volume, grain boundary (joining interface), and dislocation were separately determined from the three-dimensional distribution of 18O in the bicrystal SrTiO3. The volume diffusion of oxygen is found to be dependent on (i) Nb doping concentration, (ii) crystallographic orientation, and (iii) nonequilibrium oxygen defects that are annihilated by thermal annealing. The feature of 18O diffusion image along the dislocation in (100) and (110) bicrystals can be explained by the dislocation array introduced by the mechanical polishing.