MAGNETOELASTIC PROPERTIES OF NICKEL THIN-FILMS

The deflection of bimorphs consisting of thin films of nickel on silic on substrates has been accurately measured as a function of applied in -plane magnetic field, using an optical method. Striking differences i n the magnetoelastic behavior are observed for these systems compared with bulk nickel, mainly due to the anisotropic behavior of silicon su bstrates and to large in plane tensile stresses in nickel films, which favor an easy magnetization axis perpendicular to the film plane: Def lections measured with the magnetic held parallel and perpendicular to the length of the bimorph exhibit the same sign, and the ''parallel d eflection'' is enhanced by a factor 1.3. These are the first experimen ts demonstrating the validity of a formula recently derived for predic ting the deflection of magnetostrictive bimorphs. (C) 1996 American In stitute of Physics.