Enhanced magnetostriction through dilute Ce doping of Fe-Ga br

Doping of magnetostrictive galfenol (Fe82Ga18, in at. %) with rare-earth elements significantly enhancesmagnetostriction, with the largest gains achieved in textured melt-spun ribbons. Here, it is demonstrated thateven extremely dilute Ce, as little as 65 ppm, can double the magnetostrictive response of galfenol when coupledwith an appropriate heat treatment. This improvement is correlated with a compression of the host lattice, bothof which reach their maximum extent at the calculated solubility limit of Ce in in body-centered cubic (bcc)galfenol, similar to 50 ppm. Beyond this point, excess Ce segregates into CeGa2, which forms an interdendritic networkthroughout the sample at high Ce levels and cannot be resolutionized through heat treatments. These findingspoint to the importance of solubility limits (i.e., equilibrium thermodynamics) in determining appropriate dopinglevels or heat treatment couples to optimize magnetostrictive performance, confirming that overdoping is activelydetrimental to both material properties and cost.