ELECTRONIC-STRUCTURE CALCULATIONS ON CU(110) AND NI (110) FILMS WITH P(2 X-1) OXYGEN OVERLAYERS

We report scalar-relativistic electronic structure calculations on ultra-thin Cu(110) films and ferromagnetic Ni(110) films with p(2 × 1)-ordered oxygen chemisorbed on either side of the respective film. The latter consists of three atomic layers of Cu or Ni metal and displays a missing row reconstruction as suggested by various experiments. The calculations are carried out within a relativistic version of the density functional theory. The exchange-correlation potential has been approximated by the familiar local expressions of Gunnarsson and Lundqvist, and of v. Barth and Hedin. In solving the scalar-relativistic Kohn-Sham equations we have used the full potential linearized augmented plane wave (FLAPW) method put forward by Freeman and associates. The results on O-Cu(110) show only limited agreement with a Cu-O-Cu chain model that has been discussed in the literature and successfully been correlated with angular resolved photoemission data. In the case of O-Ni(110) we find a reduced ferromagnetic order of the top-most Ni layer, but there is a sizeable remnant moment of 0.42 bohr magnetons per atom concomitant with a finite magnetic moment of 0.17 bohr magnetons of the oxygen atoms. The latter fact gives rise to a visible exchange splitting of the excited bands. This is in keeping with recent inverse photoemission experiments. © 1990 Pergamon Press plc.