The saturation magnetostriction of permalloy films

The saturation magnetostriction of permalloy films has been measured as a function of film composition. In general, the data obtained agrees with the published values for bulk polycrystalline permalloy. It has further been established that the composition for zero magnetostriction is at about 81.5 (wt.)% Ni. The exact composition for 0 magnetostriction is difficult to attain and for most films deposited under practical conditions the magnetostriction is small but slightly negative or positive. Various elements such as Cr, Rh, Ir and Ti have been added to permalloy films to enhance their corrosion resistance. The saturation magnetostriction of these films has been measured as a function of the amount of dilutent. All of the dilutents cause positive contributions to the saturation magnetostriction of permalloy films; Ir has the largest effect on λ, with the other elements Ti, Cr and Rh the effect on λ is less than Ir and decreases in that order.