Compositional Order and Subsequent Magnetostriction in \(\mathrm{{Fe}}_{1-x}\mathrm{{Ga}}_x\) (Galfenol)

As an example of how atomic arrangements in an alloy can affect materials properties, we consider the effect of atomic ordering in the binary Fe \(_x\) Ga \(_{1-x}\) alloy, commonly referred to as Galfenol. We show that the ordered structures of interest are the B2 and D0 \(_3\) structures, and examine the influence of these chemical orderings on the Curie temperature and magnetoelastic constant of this system within a density functional theory (DFT) framework. We are able to show that these chemical orderings reduce the predicted Curie temperature of the system, but bring predicted magnetoelastic constants in to line with the measured experimental values. These results serve as an example of how atomic ordering can affect the magnetic properties of an alloy.