Half-metallicity at the non-polar surfaces of rock-salt and zinc-blende MgN

We discuss the electronic properties of non-polar surfaces of MgN rock-salt and zinc-blende crystals. We studied the (001) surface of the rock-salt and the (110) surface of the zinc-blende MgN with the use of an ab initio full-electron linearized augmented plane wave method within density functional theory. The structural parameters of the two surfaces were optimized by relaxing the position of the atoms in the unit cells in the force directions. The results of the calculations indicate that both rock-salt MgN (001) and ZB MgN (110) demonstrate half-metallic properties. The zinc-blende MgN (110) surface is electronically more stable as a half-metal than the rock-salt MgN (001) surface. The magnetic properties of the two systems are tailored mainly by the spin-polarization of electrons of N atoms.