Portal de Periódicos da CAPES

Effect of adsorbates on the spin-polarized photoemission of itinerant ferromagnets

1987; American Physical Society; Volume: 36; Issue: 7 Linguagem: Inglês

10.1103/physrevb.36.3763

1095-3795

Walter Schmitt, K.-P. Kämper, G. Güntherodt,

Advanced Chemical Physics Studies

The adsorbate systems O(2\ifmmode\times\else\texttimes\fi{}1)/Ni(110), S c(2\ifmmode\times\else\texttimes\fi{}2)/Ni(110), and O p(2\ifmmode\times\else\texttimes\fi{}2)/Fe(110) were investigated by means of spin-, angle-, and energy-resolved photoemission spectroscopy. For the Ni 3d bands with ${S}_{4}$ symmetry near the X point of the Brillouin zone we find no change of the exchange splitting due to adsorption of O and S. A majority-spin band with ${S}_{3}$ symmetry at the same k point shows a slight shift to lower binding energies under adsorption of O. For O p(2\ifmmode\times\else\texttimes\fi{}2)/Fe(110) no changes in binding energy were observed for the Fe d bands with ${\ensuremath{\Sigma}}_{1}^{\ensuremath{\downarrow}}$ and ${\ensuremath{\Sigma}}_{4}^{\ensuremath{\uparrow}}$ symmetry. Depolarization effects of the photoelectrons caused by the adsorbates are interpreted in terms of exchange scattering processes. The same scattering process gives rise to very pronounced structures in the spin-resolved spectra of S c(2\ifmmode\times\else\texttimes\fi{}2)/Ni(110). Different scattering probabilities for majority and minority electrons indicate that O and S on Ni(110) are polarized parallel to the Ni bulk spin polarization.