Random walks and correlation factor in diffusion in a three-dimensional lattice with coordination number 8

Abstract

Random-walk properties are calculated for a three-dimensional lattice with coordination number B. The new lattice consists of the mid-points of the edges of a simple-cubic lattice. Since niobium and oxygen atoms in niobium monoxide arrange themselves in this way, the lattice is referred to as the NbO lattice. The values of the return probability pr and correlation factor / for tracer diffusion via the vacancy mechanism are compared with those for other three-dimensional lattices so far reported; pr decreases and / increases with increasing coordination number of the lattices.

It is suggested that the determination of the correlation factors for the Nb or O diffusivities in NbO is helpful in clarifying the mechanism of diffusion.