Magnetization curves, (dot) experimentally acquired and (line) obtained from multiplet calculations, for Co on h-BN/Ru(0001) and h-BN/Ir(111) at both normal and grazing incidence . Lower panels: corresponding field splitting of the Co lower states obtained from multiX multiplet calculations.

Large effect of metal substrate on magnetic anisotropy of Co on hexagonal Boron Nitride


We combine x-ray absorption spectroscopy and x-ray magnetic circular dichroism with first principles density functional theory calculations and a multi-orbital many-body Hamiltonian approach to understand the electronic and magnetic properties of Co atoms adsorbed on hexagonal boron nitride (h-BN) grown on Ru(0001) and on Ir(111) substrates. The x-ray spectral shape reveals, for both substrates, an electronic configuration close to 3d8, corresponding to a spin S=1. We observe a large out-of-plane magnetic anisotropy (14 meV) for Co on h-BN/Ru(0001), while Co on on h-BN/Ir(111) is almost isotropic. Our analysis reveals that the dissimilar magnetic anisotropy originates from different Co adsorption sites, namely atop-N on h-BN/Ru(0001) and 6-fold hollow on h-BN/Ir(111).