Ab initio study of Mn adsorption on w-BN(0 0 0 1) surface

We have carried out total energy calculations to study the adsorption energy of Mn on w-BN(0 0 0 1) surface in a 2×22×2 structure. The surface is modeled using the repeated slabs approach. The calculation was performed solving the Kohn-Sham equation with a plane wave-pseudopotential approach and the generalized gradient approximation (GGA), using the Quantum-Espresso package. We find that with a Mn adatom, the w-BN(0 0 0 1) lateral surface relaxation was around some hundredth of A˚. To study the most favorable Mn adsorption configuration we considered T1T1, T4T4 and H3H3 special points. We predict that the Mn-T4T4 structure is the most energetically favorable. We find that the adsorption of a Mn atom on top of a B atom (T1T1 site) is totally unfavorable. The calculated potential energy to describe the diffusion of a Mn atom on w-BN(0 0 0 1) shows an energy barrier of 0.708 eV. From the density of states with polarized spin we discuss the magnetic effect of Mn on w-BN(0 0 0 1) surface.