Spin-resolved photoemission from the (111) face of a platinum.

Abstract

Spin and momentum of electrons emitted normally from the (111) face of a platinum single crystal by irradiation of circularly polarized light have been measured at the Berlin storage ring BESSY. The main features of the spectra could unambiguously be identified as direct transitions into a final-state band with ${\ensuremath{\Lambda}}_{6}^{1}$ symmetry. The matrix element behavior of a special transition supports the suggestion by Wern et al. [Z. Phys. B. 60, 293 (1985)] to shift the one-electron states above the Fermi energy upward by 0.7 eV as an approximation to the excited states, though the experimental band mapping indicates that this shift should be energy dependent. Furthermore, a contribution of a second final-state band could be identified by our spin-resolving technique. Another positively polarized structure at the Fermi edge showing no detectable dispersion could not be interpreted in terms of direct bulk transitions. It is tentatively attributed to emission from a surface resonance.