Phase Stability in 3d-5d (NiPt and CuAu) and 3d-4d (NiPd and CuAg) Systems

TL;DR

This paper investigates how relativistic effects influence the phase stability and magnetic properties of 3d-5d and 3d-4d alloys, revealing key differences in stability and magnetism due to band separation.

Contribution

It demonstrates the significant role of relativistic corrections in determining phase stability and magnetic behavior in specific alloy systems, a novel insight in alloy physics.

Findings

Relativistic corrections affect phase stability in NiPt, CuAu, NiPd, and CuAg alloys.

Magnetic properties of NiPd and NiPt alloys are altered by relativistic effects.

The study links band separation to changes in magnetic moments and transition temperatures.

Abstract

We show the differences in the stability of 3d-5d (NiPt and CuAu) and 3d-4d (NiPd and CuAg) alloys arise mainly due to relativistic corrections. The magnetic properties of disordered NiPd and NiPt alloys also differ due to these corrections which lead to increase in the separation between s-d bands of 5d elements in these alloys. For the magnetic case we analyze the results in terms of splitting of majority and minority spin d-band centers of the 3d elements. We further examine the effect of relativistic corrections to the pair energies and order disorder transition temperatures in these alloys. The magnetic moments and Curie temperatures have also been studied along with the short range ordering/segregation effects in NiPt/NiPd alloys.