Complex three-dimensional magnetic ordering in ultrathin films of fcc Co upon deposition of Cu

Abstract

We present an ab initio analysis of easy magnetization axis ``switching'' recently discovered in experiments on Co ultrathin films with a deposited submonolayer of Cu. The present large scale calculations show that the nanomagnetic pattern of a stepped Co(001) surface 2–3 monolayers thick with submonolayer quantities of Cu has a complex three-dimensional character. We show that the maximum noncollinearity of spin directions is about 30°, and the ``switching'' has a reentrant character as a function of Co coverage.