Spin-resolved core and valence electron photoemission from non-epitaxially grown Pb layers on Pt(111)

Abstract

The core and valence levels of Pb adsorbates on Pt(111) have been studied by means of spin, angle and energy-resolved photoemission with circularly polarized synchrotron radiation of BESSY. For an eight layer Stranski-Krastanov grown Pb adsorbate (which is thus non-epitaxial) the d core level peaks show a spin-orbit splitting of 2.7 eV and no shift with photon energy. Spin-resolved photoemission for normal light incidence and normal electron emisson from the 5 d 5 2 level reveals a m j splitting in addition to the spin-orbit splitting and in addition to the core level shifts known. The valence levels were studied with photon energies of about 12 eV. Two peaks corresponding to the 6 p 3 2 and 6 p 1 2 -derived levels could be detected for the highly symmetrical setup of normal light incidence and normal electron emission. Off normal electron emission from the 6 p 3 2 - derived level yields the opposite sign polarization component parallel to the photon spin when compared to the normal electron emission results. This is in agreement with earlier photoionization studies of free Pb atoms.