Antiferromagnetic polarization at Mn/V(001) interfaces

The magnetic map of a few Mn monolayers on V(001) substrates is investigated by ab initio density-functional theory within a generalized gradient approximation. We have found that a perfect layer-by-layer growth of the Mn film on V(001) is unstable against interdiffusion between Mn and V at the interface. The magnetic ground states found in the range of 1–3 monolayers (ML) of Mn present layered antiparallel couplings with high magnetic moments at the surface Mn atoms $\left(\sim 3{\mu }_B\right).\mathrm{}$ A buried Mn ML is shown to be more stable than the Mn monolayer on the V(001) surface and the 2-ML MnV/V(001) surface ordered alloy. A buried alloy, i.e., V/Mn-V/V(001), is also found more stable as compared to clustering Mn buried ML in V(001), and to a clean V(001) surface, whereas the surface ordered alloy is instable against the Mn overlayer and clean V(001) surface. As for the effect of magnetism on the stability of a monolayer with respect to a bilayer, we show that the formation energy sign changes from the paramagnetic to the spin-polarized case.