Band structure of the magnetic fcc pseudomorphs: Ni(100), Co(100), and Fe(100)

We report angle-resolved inverse-photoemission spectroscopy and ultraviolet-photoemission-spectroscopy measurements of the electronic structure of Cu(100), Ni(100), and pseudomorphic films of fcc Co and Fe on Cu(100). The unoccupied critical points at X are determined. These results are combined with recent photoemission data for use as input to an empirical combined-interpolation-scheme calculation of the energy-band dispersions for the allowed bands at ${\mathit{k}}^{\mathrm{\parallel }}$=0. The ferromagnetic exchange splittings of the ${\mathrm{\Delta }}_5$-symmetry 3d bands are estimated to be Δ${\mathit{E}}_{\mathrm{ex}}$=0.3 eV, 1.2 eV, and 1.2 eV for Ni(100), Co(100), and Fe(100), respectively. The exchange splitting of the fcc Fe indicates that films deposited at room temperature are in the predicted low-spin magnetic phase. Annealing the Fe films produces a paramagnetic phase that exhibits no exchange splitting.