Formation of large local magnetic moments at the Cr/Au(100) interface: Evidence for a diffuse interface

Core-level photoemission experiments on the Cr/Au(100) interface formed at ≈120°C reveal dramatic multiplet structure indicating the presence of large local magnetic moments ($\approx 4.9{\mu }_B$) on the Cr species. Surprisingly, these features persist up to approximately three Cr monolayers along with important chemical shifts and a Cr-induced valence-band peak at ≈1 eV binding energy. The latter is interpreted as a magnetic virtual Cr $3d$ bound state, and it is proposed that the first Cr monolayers form a substitutional fcc alloy with the Au substrate but above approximately five monolayers epitaxial bcc Cr layers can be achieved.