Journal ArticleDOI
Single-band model of substitutional disordered ternary alloys in the coherent-potential approximation
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In this article, the authors extended the single-band model Hamiltonian used by Velicky, Kirkpatrick, and Ehrenreich (VKE) in their classic paper on the electronic theory of nondilute binary alloys is extended to the ternary-alloy case, and a number of results are derived.Abstract:
The single-band model Hamiltonian used by Velick\'y, Kirkpatrick, and Ehrenreich (VKE) in their classic paper on the electronic theory of nondilute binary alloys is extended to the ternary-alloy case, and a number of results are derived. It is shown by direct calculation that the coherent-potential approximation (CPA) preserves the first seven moments of the density of states and the spectral density. Diagrammatic considerations put the highest moments at eight and seven, respectively. Exact information concerning the effective Hamiltonian leads via the Kramers-Kronig dispersion relation to a series of sum rules involving the self-energy. The localization theorem predicts the existence of two or three well-separated subbands for which the self-energy may have a pole between adjacent subbands. These singularities are also found in the CPA. Within the appropriate limits, all calculated quantities and various limiting behaviors (virtual crystal, dilute alloy, and the atomic limit), reduce to the binary-alloy results of VKE. A semielliptic reference density of states is used for a numerical presentation of the CPA description of the model ternary alloy. New numerical examples of the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$-independent properties of the CPA are exhibited for the self-energy, the total density of states, and the partial densities of states, over a wide range of concentrations and scattering-potential strengths. Results are also displayed for the Bloch-wave spectral density. This $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$-dependent quantity provides information concerning the validity of describing the states of the disordered alloy in terms of quasiparticles with wave vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$.read more
Citations
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Journal ArticleDOI
Electronic transport in disordered alloys: effect of thermal and off-diagonal disorder
TL;DR: In this article, the coherent potential approximation is applied to the DC electrical conductivity of substitutionally disordered off-diagonal binary and ternary alloys in the presence of phonons.
Journal ArticleDOI
Calculation of the DC electrical conductivity of the disordered ternary alloys
K I Wysokinski,M Pilat +1 more
TL;DR: In this paper, the coherent potential approximation is applied to a study of the DC electrical conductivity at zero temperature of disordered ternary alloys, where a semielliptical density of states is used for numerical purposes.
Journal ArticleDOI
Spin‐disorder resistivity of ternary alloys in the CPA weak scattering limit
F. Goedsche,G. Vojta +1 more
Journal ArticleDOI
Statistical Theory of Electrical Resistivity of Magnetic Ternary Alloys with Partial Long-Range Order
R. Richter,F. Goedsche,G. Vojta +2 more
TL;DR: In this paper, a closed resistivity formula in terms of alloy, spin, and order parameters is given in second order of the scattering potential and discussed for a number of special cases including antiferromagnetic ordering.
Journal ArticleDOI
Effect of temperature on the off-diagonal alloy properties
K. I. Wysokiński,M. Piłat +1 more
TL;DR: In this paper, a tight-binding one-band Hamiltonian including diagonal thermal and diagonal and off-diagonal substitutional disorders was used to study the density of states and the conductivity of binary and/or ternary alloys.
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