First-principles study of ordering properties of substitutional alloys using the generalized perturbation method

A Comparative Study of Short Range Order in Fe-Cr and Fe-V Alloys Around Equiatomic Composition

Configurational energies have been calculated for equiatomic Fe-Cr and Fe-V alloys possessing the high temperature bcc crystalline structure, within a first principles electronic band structure approach. In agreement with experimental facts, a tendency towards order, with a B2 ordered structure of CsCI type, is found for FeV whereas phase separation characterizes FeCr. These results suggest that the nature of short range order in the high temperature bcc solid solution is not the primary driving force for describing the structural transformation from bcc to sigma which takes place in both alloys upon decreasing temperature.

A First-Principles Study of Short Range Order in Cu-Zn

Recently, measurements of short-range order (SRO) diffuse neutron scattering intensity have been performed on quenched Cu-Zn alloys with 22.4 to 31.1 atomic percent (a/o) Zn, and pair interactions were obtained by Inverse Monte Carlo simulation [1]. These results are compared to SRO intensities and effective pair interactions obtained from first-principles electronic structure calculations. The theoretical SRO intensities were calculated with the Cluster Variation Method (CVM) in the tetrahedron-octahedron approximation with first-principles pair interactions as input. More generally, phase stability in the Cu-Zn alloy system is discussed, using ab-initio energetic properties.

First-principles KKR-CPA calculation of interactions between concentration fluctuations

The aim of this work is to develop the method of calculating atomic interactions in metals and semiconductors on the basis of first-principles electronic structure calculation. A new method to calculate the atomic interactions in the framework of KKR-CPA is proposed. In this approach two specific atoms embedded in a CPA medium are considered and the effects of both electron-electron interactions and multiple scattering, which are neglected in the generalized perturbation method (GPM), are fully taken into account. The calculated atomic interactions show that these effects are important for alloys containing transition-metal alloys such as FeAl. On the other hand, in the case of AuCu, where the d states lie considerably below the Fermi level, the effects are less important.