Ab initio investigations on atomistic behaviors and magnetic properties in Fe-Cu multilayer system

摘要

Using the density functional theory calculations, the surface diffusion and incorporation processes for Fe-Cu multilayer system were investigated. The minimum energy path calculations revealed that the hollow site of Cu(001) and Fe(001) surfaces was the most stable adsorption site, and the energy barriers for the surface diffusion were 1.04 eV for Fe/Cu(001) and 0.50 eV for Cu/Fe(001) systems. During the process, small fluctuation of magnetic moment, as amount of 0.11 μ_B for Fe adatom and 0.02μ_B for Cu adatom, was observed. The energy barrier for the incorporation of the Fe adatom into the surface layer of Cu substrate was 0.75 eV, and the energy gain of the system was 0.92 eV. At the substitutional site, the magnetic moment for Fe adatom was decreased by 2.64μ_B. The Cu adatom required a relatively small energy barrier, 0.50 eV, for incorporation into the Fe substrate; however, it was found that, after the process, the total energy was rather increased by 0.37 eV.