Effect of 2 MeV Fe3+ irradiation on Fe atom site population in a sigma-phase Fe-Cr compound

TL;DR

This study investigates how 2 MeV Fe3+ ion irradiation affects the distribution of Fe atoms among different lattice sites in a sigma-phase Fe-Cr alloy, revealing temperature-dependent site redistribution patterns.

Contribution

It provides new insights into irradiation-induced atomic redistribution in sigma-phase Fe-Cr alloys using Mössbauer spectroscopy across various temperatures.

Findings

Fe atom redistribution depends on irradiation temperature.

Maximum redistribution occurs at 300°C.

No site occupancy change at 700°C.

Abstract

A sigma-Fe54.5Cr45.5 samples irradiated in vacuum with 2 MeV Fe3+ ions at 300, 400, 475 and 700 deg C to the maximum dose of 12.5 dpa were studied with the conversion electron M\"ossbauer spectroscopy (CEMS). The analysis of the room temperature CEMS spectra revealed an irradiation-induced redistribution of Fe atoms viz. their number on B and D sites decreased while on A, C and E sites increased. The degree of the redistribution was found to be proportional to the number of Fe atoms present on the lattice sites in the non-irradiated samples. The highest degree of the redistribution was revealed in the sample irradiated at 300 deg C. No change in the site occupancy was found in the sample irradiated at 700 deg C.