Magnetostriction and in-situ measurement of stress of Co/Pd compositionally modulated multilayer films during fabrication

The internal stress (σ_int) at the interface of each layer of Co(8 Å)/Pd (40 Å) compositionally modulated multilayer film (CMF) was successfully measured with the aim of evaluating stress-induced anisotropy. The CMF was prepared by vacuum evaporation, and the in situ measurement of σ_int was done during fabrication. It was clarified that the Co layer was subject to constant large tensile stress from the Pd layer. This stress was much smaller than that estimated according to the lattice mismatch between Co and Pd. It was also found that Pd layer evaporated on Co layer was subject to compressive stress; however, it extended over only one or two monolayers before changing to tensile stress again. For the sputtered films, the magnetostriction constants were measured, and the relationship between perpendicular magnetic anisotropy and stress-induced anisotropy was examined