Simple metal binary phases based on the body centered cubic structure: electronic origin of distortions and superlattices

TL;DR

This paper investigates the electronic origins of distortions and superlattices in binary phases based on the body centered cubic structure, emphasizing Fermi surface interactions and their role in phase stability.

Contribution

It introduces a Fermi sphere-Brillouin zone interaction analysis to explain distortions and superlattice formation in noble metal alloys with BCC structures.

Findings

Fermi surface interactions significantly influence phase distortions.

Electronic energy contributions are key to superlattice stability.

Method may explain complex structures in compressed alkali metals.

Abstract

Binary alloy phases of the noble metals with main group elements are analyzed in relation to body centered cubic structure with orthorhombic and hexagonal distortions. Stability of these distorted phases is considered on the base of the Fermi sphere - Brillouin zone interaction to understand the important part of the band structure energy contribution to the overall crystal energy. Examination of Brillouin zone - Fermi sphere configurations for several representative phases has shown significance of the electron energy contribution in the formation of distorted structures with superlattices and ordered vacancies. This approach may be useful for understanding recently found complex structures in compressed simple alkali metals.