Magnetic structure of fcc Fe on Cu(111)

We report ab initio calculations on the magnetic structure of fcc Fe films on Cu(111) for a coverage up to 6 ML considering all possible collinear spin orders in the p(1×1) surface cell. The total magnetic moment of the film undergoes a high-to-low spin transition around 3 ML coverage, in agreement with recent experiments. The spin transition is due to the competition between surface/interface effects with enhanced moments and preferentially ferromagnetic coupling between adjacent monolayers on the one hand and bulklike spin-density wave correlations with a wavelength of about 3 ML on the other hand.