Photoemission anisotropy studies for ag(111) and ag(100) single crystal films₁.

Abstract

Photoemission energy distributions (EDC's) and quantum yields are reported for s-p band emission from oriented single crystal films of Ag(111) and Ag(100) for photon energies 5 hv 11.6 eV. Results for this simple system, in which only transitions between one pair of s-p bands occur with hv 8 eV, are compared with the predictions of the simple three-step volume photoemission model for a nearly-free-electron metal. Structure in the EDC's can be fit by this model with a "band mass" m*/m0= 1.0 ± 0.04 in the T-L direction. However, an unexpected lack of anisotropy between (100) and (111) oriented Ag surfaces is observed which appears to indicate predominant diffuse surface refraction, rather than specular surface refraction as is usually assumed. The yield was measured as a function of the angle of incidence of the light for Ag(111), and for the most part shows very little correlation with a calculated yield based on bulk excitations. © 1973 IOP Publishing Ltd.