Manipulation of spin reorientation transition by Au capping in body-centered cubic Ni(001) film

The thickness dependent magnetic properties of artificially prepared ultrathin body-centered cubic Ni films have been explored using the all electron full potential linearized augmented plane wave (FLAPW) method. We have considered two types of BCC Ni(001) films: (i) pure BCC Ni(001) and (ii) Au capped BCC Ni(001) in the range from 1 monolayer (ML) to 4 ML of Au capping coverage. The average magnetic moment of pure BCC Ni(001) is about 0.63 mu(B) and a typical surface enhancement is found with a magnetic moment of 0.78 mu(B). In the presence of an Au capping layer, the magnetic moment of interface Ni is strongly suppressed to approximately 0.5 mu(B) and this causes a reduction of average magnetic moment. Nevertheless, the Au adlayer has no meaningful induced magnetic moment. The BCC pure Ni(001) films always have in-plane magnetization up to 11 ML, but very interestingly the Au/ Ni(001) shows a thickness dependent spin reorientation transition (SRT) from in-plane to perpendicular to the film surface. However, the thickness dependent SRT shows very irregular behavior. In addition, the calculated x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) have been presented.