Theoretical Investigation Of The Spin Reorientation Transition In Epitaxial Films Of NiO

We study theoretically the spin reorientation transition in thin epitaxial films of NiO grown on Ag and MgO. Experimentally, the Ni spins point out‐of‐plane for films grown on the MgO substrate and in‐plane for those on the Ag substrate. We successfully explain these opposite trends in the ground state moments for the two cases and simulate the isotropic x‐ray absorption spectrum (XAS) for bulk NiO, in good agreement with experiments, on the basis of cluster configuration interaction calculations based on a $NiO6$ cluster.