Magnetoelastic properties of nickel thin films

The deflection of bimorphs consisting of thin films of nickel on silicon substrates has been accurately measured as a function of applied in‐plane magnetic field, using an optical method. Striking differences in the magnetoelastic behavior are observed for these systems compared with bulk nickel, mainly due to the anisotropic behavior of silicon substrates and to large in plane tensile stresses in nickel films, which favor an easy magnetization axis perpendicular to the film plane: Deflections measured with the magnetic field parallel and perpendicular to the length of the bimorph exhibit the same sign, and the ‘‘parallel deflection’’ is enhanced by a factor 1.3. These are the first experiments demonstrating the validity of a formula recently derived for predicting the deflection of magnetostrictive bimorphs.