Photoemission Studies of Platinum

Abstract

Photoelectron energy-distribution curves of Pt at photon energies $6.8\ensuremath{\le}\ensuremath{\hbar}\ensuremath{\omega}\ensuremath{\le}11.6$ eV exhibit structure originating from initial states 3.6, 2.5, 1.5, and between 0.7 and 0.2 eV below ${E}_{F}$. A strong peak at - 0.2 eV observed for $\ensuremath{\hbar}\ensuremath{\omega}<9.1$ eV is joined by a second peak at - 0.7 eV in the range $\ensuremath{\hbar}\ensuremath{\omega}=9.1\ensuremath{-}9.7$ eV. Above 9.7 eV, the two peaks merge to a single rounded peak at - 0.5 eV which grows stronger and sharper at higher photon energy. Good correspondence is found between structure in the energy-distribution curves and in a calculated band density of states. The results are discussed in terms of the direct and nondirect models of optical excitation and compared to similar results from Ni, Pd, and Rh.