Gk. Wertheim et Dm. Riffe, EVIDENCE FOR CRYSTAL-FIELD SPLITTING IN SURFACE-ATOM PHOTOEMISSION FROM POTASSIUM, Physical review. B, Condensed matter, 52(20), 1995, pp. 14906-14910
Photoemission spectra from the shallow 3p(3/2) core levels of the surf
ace atoms of metallic potassium exhibit the effects of a small but mea
surable crystal-field splitting of similar to 38 meV. It manifests its
elf mainly as an apparent angle-dependent modulation of the spin-orbit
splitting. This phenomenon may, in general, interfere with accurate d
eterminations of surface-atom core-level shifts.