Sigma-phase in the Fe-Re alloy system: experimental and theoretical studies

TL;DR

This study combines experimental techniques and theoretical calculations to analyze the structural and electronic properties of sigma-phase Fe-Re alloys, providing detailed insights into site occupancies and charge densities.

Contribution

It is the first to integrate XRD, Mössbauer spectroscopy, and KKR calculations to comprehensively study sigma-phase Fe-Re alloys.

Findings

Successful decomposition of Mössbauer spectra into five sublattice components.

Determination of site occupancies and lattice constants from XRD.

Calculation of charge densities and quadrupole splittings matching experimental data.

Abstract

X-ray diffraction (XRD) and M\"ossbauer spectroscopy techniques combined with theoretical calculations based on the Korringa-Kohn-Rostoker (KKR) electronic structure calculation method were used to investigate \sigma-phase Fe_{100-x}Re_{x} alloys (x = 43, 45, 47, 49 and 53). Structural data such as site occupancies and lattice constants were derived from the XRD patters, while the average isomer shift and distribution curves of the quadrupole splitting were obtained from the M\"ossbauer spectra. Fe-site charge-densities and the quadrupole splittings were computed with the KKR method for each lattice site. The calculated quantities combined with the experimentally determined site occupancies were successfully used to decompose the measured M\"ossbauer spectra into five components corresponding to the five sublattices.