Magnetism of a vanadium monolayer on Ag(100): Experiment versus theory

We have studied the magnetic and structural properties of a vanadium monolayer deposited on an Ag(100) surface. Several theoretical studies have predicted an enhanced magnetic moment on vanadium and ferromagnetic order for such a film. No magnetic signal has been detected by means of X-ray magnetic circular dichroism. This result rules out any possible ferromagnetic spin arrangement. We have used scanning tunnelling microscopy in order to find an origin for the discrepancy between theoretical and experimental results. STM images of a vanadium deposition corresponding to 1 monolayer thickness reveal that vanadium grows in an island mode and the monolayer structure cannot be stabilized. This is in clear contrast with theoretical calculations that has been performed assuming an ideal vanadium monolayer slab