Zero magnetostriction iron films

Iron films with low coercive force and near-zero magnetostriction have been prepared by ion beam sputtering. With an increase in Ar ion acceleration voltage, the dominant crystalline orientation of the films changed from the (100) to the (110) plane. The saturation magnetostriction constant, λ_s, changed from positive to negative values, corresponding to the orientation change. The λ_s of annealed films, whose lattice constants agreed well with those of the bulk, were close to the calculated values. The coercive force had a minimum of about 2 Oe near zero λ_s. The results indicate that the soft magnetic properties of iron films can be improved by reducing λ_s, which in turn is controlled by the acceleration voltage of the ion-beam-sputtering system