Magnetic in-plane anisotropy in sputtered FeCo films and multilayers

Recent publications report a magnetic in-plane anisotropy in FeCo films and multilayers. This property can be exploited for example to polarize neutrons in a small external field and the remanent magnetization can serve to use the mirrors as a spin selective device. In this work a study on Fe0.50Co0.48V0.02 films and multilayers in combination with Ti:N has been performed with regard to the connection between stress in the coating and the in-plane anisotropy using SQUID and MOKE magnetometry as well as mechanical and X-ray stress analysis. The results prove the magnetostrictive nature of the anisotropy resulting from the condensation of sputtered particles arriving at the surface under oblique incidence. The dependence of the remanence on the thickness of the deposited layer is accentuated in this work. For samples as old as two years we have observed a small degree of stress relaxation. (author) 5 figs., 7 refs