Magnetic surface and magnetoelastic interface anisotropies in epitaxial Au/Co and Ag/Co superlattices

In situ observations of reflection high-energy electron diffraction and Co-layer-thickness dependence of magnetic anisotropy in epitaxial (111)Au/Co, Ag/Co, Au/Co/Ag, and Ag/Co/Au superlattices indicate that the two interfaces of each Co layer in the Au/Co superlattices are not identical and that the magnetoelastic interface anisotropy arises only from the Au/Co interfaces formed upon depositing Co on Au layers. It has been demonstrated that the magnetoelastic interface and the Ne{}el-type magnetic surface anisotropies contributing to the perpendicular magnetic anisotropy can be separately estimated. Saturation of magnetic anisotropy energy at small Co-layer thickness was discussed in terms of the gradient in Co-layer strains.