Possible magnetism of Rh as an overlayer on Cu(0 0 1): A first-principles study

Abstract

Possible two-dimensional magnetism of a Rh monolayer on the Cu(0 0 1) substrate was investigated using the full-potential linearized augmented plane-wave (FLAPW) method. The equilibrium interlayer distance between Rh and the adjacent Cu layer was determined through total-energy calculations (3.58 a.u.). We find that the Rh monolayer on Cu(0 0 1) can be magnetic, as suggested in a recent experiment. However, the total energy difference between the ferromagnetic (FM) and paramagnetic (PM) states is found to be very small and, hence, only observable at very low temperature. The calculated FM moment of Rh, 0.23 μ B, on Cu(0 0 1), is considerably smaller than that (0.96 μ B) on Ag(0 0 1) due to the much smaller lattice constant in the lateral plane and, hence, the stronger band hybridization between the Cu and Rh layers.