Coherent Potential Method in the Electronic Theory of Disordered Alloys

Abstract

A general solution of the problem of multiple scattering on a localized random potential is achieved in a single-band model of diagonal disorder for a binary substitutional alloy. A configurationally averaged (T)-matrix is presented as a cluster-type expansion. The short-range order effect on the electronic spectrum, specific heat capacity, and residual electrical conductivity is studied with regard to the multiple scattering on a two-particle cluster (on pairs of atoms) for the coherent potential satisfying the condition of the single-site approximation. Expressions for the electronic density of states and electrical conductivity (allowing for the scattering on pairs) are presented in an analytical form.

THE SHORT-RANGE ORDER AND ITS INFLUENCE ON RADIATION STABILITY OF LOW-CONCENTRATION Fe-Cr ALLOYS

“…In particular, the formation of SRO in the alloy is accompanied by a noticeable decrease in the density of electronic states at the Fermi level [27]. The forces of electronic interaction between atoms, determined by the position of the Fermi level in the electron band, will change not only in magnitude but also in sign [18,19,28].…”

Short‐Range Order in Binary Solid Solutions The Change of Electronic Density of States on Ordering

“…We take into account the contributions of the scattering processes on pairs of atoms neglecting the contributions of clusters consisting of three and more atoms. In this case, the electronic density of states g(E) per atom can be presented in the form [2] (xY~E, + a m ) arn[(l -x~a i )…”

Criterion of applicability of coherent-potential approximation at low impurity concentrations

“…Since the CPA was supposed to fail near the band edges according to [5], it was suggested that this expression can be used to judge the CPA's validity. This criterion was successfully implemented in a series of CPA-based calculations for short-range order alloys [10,11]. Nevertheless, its physical meaning remained quite vague and it was not clear how close one could approach unity and still rely on the CPA results.…”