A new neutron study of the short range order inversion in Fe$_{1-x}$Cr$_x$

TL;DR

This study uses neutron diffuse scattering to precisely analyze the short-range order inversion in Fe$_{1-x}$Cr$_x$ alloys, identifying the critical concentration and characterizing atomic interactions.

Contribution

It provides new experimental data on short-range order inversion in Fe-Cr alloys, including accurate determination of the inversion concentration and atomic pair potentials.

Findings

Inversion concentration x₀ = 0.110(5) identified

Short-range order parameters change sign at x₀

Experimental results align with first-principles calculations

Abstract

We have performed new neutron diffuse scattering measurements in Fe$_{1-x}$Cr$_x$ solid solutions, in a concentration range 0$<$x$<$0.15, where the atomic distribution shows an inversion of the short range order. By optimizing the signal-background ratio, we obtain an accurate determination of the concentration of inversion x$_0$ =0.110(5). We determine the near neighbor atomic short range order parameters and pair potentials, which change sign at x$_0$. The experimental results are compared with previous first principle calculations and atomistic simulations.