Engineering of magnetostriction in Fe3Pt1-xIrx by controlling the Ir concentration

A tremendous change in both the sign and magnitude of magnetostriction (lambda(001)) in Fe3Pt1-xIrx (x=0-1.0) was discovered through a first-principles study using the highly precise full-potential linearized augmented plane wave method. The obtained lambda(001) values span a wide range from -1050 (x=0) to +2670 ppm (x=0.25), a significantly large enhancement over the lambda(001) values attained for Galfenol, a widely investigated material. Further analysis confirmed that this large effect originates mainly from the nonmagnetic Ir and Pt with induced moments, of which the 5d orbital has larger spin-orbit coupling than the 3d orbital of Fe. (C) 2011 American Institute of Physics. [doi:10.1063/1.3578190]