ORIGIN OF VERY LARGE INPLANE ANISOTROPIES IN (110)-ORIENTED CO/PD AND CO/PT COHERENT SUPERLATTICES

Within the framework of a continuum free-energy calculation we show that the experimentally observed large uniaxial in-plane anisotropy in epitaxial single-crystal (110)-oriented Co/Pt and Co/Pd superlattices is caused by the magnetoelastic interaction as well as anisotropic lattice distortion, a process unique to coherently strained ultrathin layers. We find in agreement with existing experimental data that the easy axis is aligned in plane along the [001] axis, contrary to bulk cobalt, and that the absolute value of the anisotropy constant is dependent on the intermixing at the interfaces.