Empty electronic states at the (1×1) and (5×20) surfaces of Pt(100): An inverse photoemission study

Abstract

We have measured angle-dependent inverse photoemission spectra in the isochromat mode (photon energy hw=9.5 eV) from the (1×1) and (5×20) surfaces of Pt(100). In addition, the sample to ground current was studied at normal incidence as a function of the electron kinetic energy. The isochromat results show clean evidence for bulk band transitions which are intensity-modulated by the reconstruction. Their energy positions remain, however, stationary. Transitions into image potential states located outside the surface are observed on both faces at 0.6±0.2 eV below the vacuum level. A surface band located near the X̄ point of the surface Brillouin zone is identified on the (1×1) surface. The analysis of the bulk transitions in combination with the sample current data and earlier photoemission studies of other authors allows the determination of several bulk band energies above E F . Good agreement with a recent band structure calculation is observed.