First-principles studies on (0Â 0Â 1) surface electronic bonding and magnetic properties of ZnCMn3 and ZnNMn3 intermetallic antiperovskites type compounds

We present the Mechanical, electronic and magnetic properties of the cubic intermetallic antiperovskites ZnCMn3 and ZnNMn3 in both bulks and (0 0 1) surface tetragonal slabs geometries. The calculations are based on the plane wave pseudo potential method (PP-PW) within spin polarized Generalized Gradient Approximation (GGA) of the exchange-correlation functional. Lattice parameters were found to be in agreement with available experimental results. In contrast of Bulk ZnCMn3, ZnNMn3 was mechanically instable up to 157 MPa and shows a very weak resistance to elastic shear deformation. ZnNMn3(0 0 1) Surface was found to be slightly stable than that of ZnCMn3. More investigations reveal that the calculated magnetic moments per manganese atom (Mm/atom) are about 2.62 and 2.82 μB when replacing C by N respectively. Using the total density (number) of states TDOS (TNOS) and the projected ones PDOS (PNOS) we prove that total and manganese magnetic moments are mostly derived from Fed atoms states at the vicinity of Fermi level. TNOS and PNOS analysis prove that metallic character was assigned to major spin down (↓) participation. Magnetic moment of bulks structure are about 7.02, 7.82 μB, when replacing C by N respectively which is somewhat conserved at surface geometries.