Characterising antiphase domains in FeCo alloys

FeCo soft magnetic alloys are considered essential for the electrification of civil aviation. However, their reliable use requires an improved understanding of how their properties change with processing. These changes are associated with ordering from the A2 (bcc) to B2 (CsCl) structure, leading to antiphase domains. In this experiment, high-resolution powder diffraction data will be acquired from 6 solid FeCo alloy samples ex situ with different levels of order produced by quenching at controlled rates and 4 disordered samples heated in situ at temperatures from 470-600ᵒC. The high brilliance at high energy and low instrumental broadening of ID22 will allow quantification of the antiphase domain size from line profile analysis of the superlattice reflections. The size of the antiphase domains is hypothesised to be a key factor in determining the magnetic structure at this scale and hence could help explain why the magnetic properties change with different processing conditions.