Diffusion Mechanism in Ordered Alloys —A Detailed Analysis of Six-Jump Vacancy Cycle in a Two-Dimensional Ordered Lattice—

Atom movements via six-jump vacancy cycle are analysed in detail for a two-dimensional ordered alloy, AB. The diffusion coefficients, DA and DB, are expressible in terms of the effective jump frequency, ν, for the six-jump vacancy cycle, and the correlation factors, fA and fB. By applying the theory of stochastic processes, the analytical expression for ν is derived in terms of six individual jump frequencies of vacancy. The correlation factors, fA and fB, can be calculated exactly: fA=1(π−1), fB=π⁄(π+2).