Measurement of Magnetoelastic Effect for Isotropic Thick Alloy Films

While there are numerous reports on the magnetoelastic (magnetostrictive) effect in uniaxially anisotropic soft magnetic films, no such studies have been reported for isotropic films. A strain gauge and B-H meter were used to determine the anisotropy fields ¿Hk induced by uniaxial strain e in an isotropic Fe-Si-Al film, and from this found the strain sensitivity ¿. The value of ¿ thus determined was far smaller than the strain sensitivity for the bulk material. The discrepancy may be explained by the application of a model for anisotropic samples to isotropic films, or to a small reverse magnetostriction effect.