Spin-resolved off-normal photoemission from xenon adsorbates in comparison with free-atom photoionization

Circularly polarized synchrotron radiation of BESSY has been used to study the angular dependence of the spin polarization of photoelectrons emitted from Xe(√3x√3)R 30° Pd(111). The spin-polarization component along the light helicity varies from +1 for normal emission to ?0.5 for emission angles larger than 45°. The data can be fitted by use of the theory for photoionization of free xenon atoms and yield the dynamical fit parametersA, α, β, ζ for the adsorbate. Good agreement is obtained with the gas phase data.