Experimental evidence of effective <111> atomic exchanges in a B2 intermetallic alloy

TL;DR

This study provides atomic-scale evidence of <111> atomic exchanges in a B2 FeAl alloy, revealing their role in diffusion and material transport, especially at moderate temperatures.

Contribution

It demonstrates the dominance of <111> atomic exchanges in FeAl B2 alloys at moderate temperatures through experimental X-ray spectroscopy.

Findings

<111> exchanges are dominant in FeAl B2 alloys.

These exchanges control long-range diffusion.

The mechanism is prominent at moderate temperatures.

Abstract

We report on an atomic-scale X-ray Photon Correlation Spectroscopy study on Fe-rich FeAl in the B2-ordered regime revealing effective <111>-exchanges of atoms on the Al-sublattice. The diffusion mechanism responsible for these exchanges is the dominating process for chemical diffusion and therefore controls long-range material transport in the system. Comparison with previous atomistic results shows that the dominance of further exchanges can be characteristic at moderate temperatures where the system is highly ordered.