Diffusion of ⁵⁷Co along grain boundaries in NiO

Abstract

The characteristic parameter αD'δ, which is the product of the segregation coefficient, the boundary diffusion coefficient and the boundary width, has been measured for the diffusion of ⁵⁷Co along both high-angle and low-angle grain boundaries in high-purity polycrystalline NiO. The measurements were made at an oxygen pressure of 1 atm at temperatures in the range 500–800°C, and at an oxygen pressure of 10⁻¹¹ atm at 700°C. The results show that the close similarity between the diffusion of Co and Ni in the NiO lattice is also true of the diffusion of Co and Ni along NiO grain boundaries.