Measurement of Magnetostriction Constants in (111)-Oriented Polycrystalline PdCo Alloy and Multilayered Films

A method for measuring magnetostriction constants λ100 and λ111 was developed for (111)-oriented polycrystalline films. Magnetostriction constants were estimated from the magnetic anisotropy induced by the application of in-plane uniaxial strain. In sputtered Pd100-x Co x alloy films, the estimated magnetostriction constants agree with those of PdCo single-crystal alloys. The magnetostriction constants of Pd/Co multilayered films (MLs), with decreasing bilayer period D, approach those of alloy with the same constitution, while with increasing D, they approach the values for fcc-Co obtained from the extrapolation of the data for the alloy films. These results are explained by the effect of electron hybridization and/or alloy formation at the interface of Pd and Co.