Magnetic structure of Fe/Cu(001) thin layers

Ab-initio fully relativistic band structure calculations of Fe films on Cu (001) substrate are presented. The films are modelled as 6Cu/nFe/6Vc slabs, where the number of multilayers (ML) is n=1, 2, 4 and 6. Intermixing between Fe atoms of the thin film and the Cu atoms of the substrate was found to be energetically favourable for 1ML coverage, causing also a decrease of the Fe magnetic moment. The mixing of deposited Fe atoms with the Cu substrate has been studied using the Coherent Potential Approximation (CPA). Various ferromagnetic and ferrimagnetic spin configurations with coupling of layer blocks have been considered, with the in-plane and out-of-plane direction of magnetization. Total energy calculations have been performed and the most stable spin configuration for unrelaxed fcc thin films are shown. While for the 1 and 2 ML Fe/Cu(001) a ferromagnetic out-of-plane spin configuration is the most stable, 4 ML and 6 ML cover regimes exhibit a spin configuration with blocks of layers ferrimagnetically coupled. Layer-resolved spin and orbital magnetic moments in the ground state configuration have also been determined for 1, 2, 4 and 6 ML coverage.