Initial and final state effects in the photoionization spin–orbit branching ratio of core levels

Abstract

We have investigated the ratio, R, of the photoionization cross sections of the In 4d5/2 and In 4d3/2 core levels on InSb (110) surfaces for energies within ∠9 eV of the threshold. We have separated for the first time the initial from the final state effects in R by employing different synchrotron radiation photoemission techniques. Energy distribution curves (EDC’s) and constant final energy spectra (CFS’s) demonstrate in particular that the R vs h/ω behavior is almost entirely determined by final state effects. This allows one to establish a relation between R and σ, the photoionization cross section, in an energy region where direct measurements of σ are made difficult by the secondary electron background.

Chemical Effect on theD522:Barth1, Gerken2, Kunz3 et al. 1985Phys. Rev. Lett.5000View full textAdd to dashboardCite

“…The measured photoemission intensities depend on the atomic cross sections, but also on photoelectron mean free path, surface refraction, and analyzer transmission, which are all dependent on the kinetic energy. 8 The latter factors describe the probability of the photoelectrons leaving the solid without being scattered inelastically and the experimental detection probability for the photoelectron (analyzer transmission) which can be determined experimentally. 5 The escape probability of photoelectrons from a solid sample has recently been investigated for Au.…”