Crystal Orientation Dependence of Magnetization and Magnetostriction Behaviors in Highly Textured Galfenol and Alfenol Thin Sheets

Highly textured rolled sheets of Fe-Ga and Fe-Al alloys behave like single crystal, exhibiting magnetostriction values that are equal to ~80%-95% of those of single crystal along the (100) axes. In this paper, we investigate the crystal orientation dependence of anisotropic magnetization and magnetostriction properties in highly textured disks of Fe-Ga and Fe-Al alloys. The highly textured samples are composed of a single (011) plane and small isolated grains, aside from the (011) grain, which exhibit three different cubic crystal orientations, such as (100), (110), and (111) directions. Measured magnetostriction values strongly depend on a deviation angle of the (100) direction from the rolling direction, well matched with the predicted values based on the anisotropic magnetostriction equation in the (011) plane. Of particular interest is the observation that measured values at the deviation angles over ~20° are higher than the predicted ones as much as the fraction of island grains with principal (100) and (110) directions along the strain measurement direction. In addition, it seems to be averaged out for magnetization behaviors along the three different directions in comparison with those of the single crystal Fe-Ga.