Coalescence of the Fermi-surface-related diffuse intensity peaks in disordered alloys

TL;DR

This paper predicts that the Fermi-surface-related diffuse intensity peaks in disordered alloys can merge as temperature decreases, due to a compensation mechanism involving self-energy and interaction curvatures, aligning with experimental observations.

Contribution

It introduces a theoretical explanation for the temperature-dependent coalescence of diffuse intensity peaks related to the Fermi surface in disordered alloys.

Findings

Predicted peak coalescence at lower temperatures.

Mechanism involves reciprocal-space curvature compensation.

Consistent with observed thermal splitting in Pt-V alloys.

Abstract

The possibility of disappearance of the diffuse-intensity peak splitting induced by the Fermi surface (i.e., of coalescence of the intensity maxima) with decreasing temperature is predicted. The underlying mechanism is the compensation of the reciprocal-space curvatures of the self-energy and the interaction. The theory also describes similar results obtained earlier for two low-dimensional models with competing interactions. The coalescence is compared with the recently observed "thermal" splitting in Pt-V which can be explained in the same way.