Perpendicular magnetic anisotropy in Pd/Co thin film layered structures

This letter presents the results of magnetic studies of thin film, periodic, Pd/Co layered structures with ultrathin cobalt (4–13 Å). We show that films with Co thicknesses less than 8 Å are easy to magnetize along a direction normal to the film surface. The best films have a saturation magnetization of about 500 emu/cm3 and a coercivity of 550 Oe, and thus they are candidates for a vertical magnetic recording medium. We attribute the perpendicular magnetic easy axis in these films to surface anisotropy at Pd/Co interfaces and strain in thin Co layers.