Analysis of the effective interatomic interactions in metallic alloys

摘要

Ab-initio studies of alloy phase stability are usually based on the Ising-type Hamil-tonian, whose parameters, often called the effective cluster interactions (ECI), serve as an input in determination of the equilibrium properties of the system via the methods of statistical mechanics. An alternative formulation, which completely avoids determination of CEIs by calculating the electronic structure and solving the statistical part of the problem in one step, is employed in the concentration-wave method~1. It is based on the grandcanonical potential OMEGA configurationally averaged~2 within the coherent potential approximation (CPA) and on a mean-field solution of the statistical part of the problem including usually also the Onsager cavity field.