Electronic band structure and Fermi surface of new low-temperature Ni-based superconductors: 3.3 K (Ni2P2)(Sr4Sc2O6) and 2.7 K (Ni2As2)(Sr4Sc2O6) from first principles

Based on first-principle FLAPW-GGA calculations, we have investigated structural and electronic properties of the recently synthesized tetragonal (space group P4/nmm) nickel-based pnictide oxide superconductors: 3.3 K (Ni2P2)(Sr4Sc2O6) and 2.7 K (Ni2As2)(Sr4Sc2O6). Optimized structural data, electronic bands, total and partial densities of states, and Fermi surface topology have been obtained and discussed in comparison with available experiments and with their Fe-based (Fe2P2)(Sr4Sc2O6) and (Fe2As2)(Sr4Sc2O6) analogs.

Research highlights
► By first-principle FLAPW-GGA approach, structural and electronic properties of nickel-based pnictide oxide SCs have been examined.
► These materials are characterized as quasi-two-dimensional non-magnetic ionic metals.
► Their Fermi surfaces are formed by four cylindrical-like sheets parallel to the kz direction, which are of electronic- and hole-type.
► The orbital components on the Fermi level are of mixed type, where all five Ni 3d orbitals as well as three Pn p orbitals are presented.