Excitation of phonons and forward focusing in x-ray photoemission from the valence band

M. A. VICENTE ALVAREZ; H. ASCOLANI; G. ZAMPIERI

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society

Lugar: New York; Año: 1996 vol. 54 p. 14703 - 14712

0163-1829

A model is presented to explain the transition of the angular distribution of valence-band photoelectrons from the low-energy regime, characterized by emission only along the Mahan cones, to the high-energy regime, characterized by emission patterns very similar to those of core-level photoelectron diffraction. The two main ingredients of the model are the excitation/absorption of phonons during the photoemission, and the multiple scattering of the electron in the final state. Using simple assumptions about the valence-band initial states of Al(001) and a Debye model to describe the lattice vibrations, we calculate angular distributions of photoelectrons that are in excellent agreement with recent experimental results.