Spin-orbit-induced spin polarization in W 4f photoemission

The photoelectron spin polarization induced by spin-orbit interaction was studied for emission out of the W 4f level excited by linearly polarized light. The polarization shows a smooth variation with photon energy, in qualitative agreement with the behavior expected for a free atom, but in contrast to recent results for Cu 3p. By determining the photon energies where the polarization vanishes the phase differences between l+1 and l-1 final-state channels are found to take on multiples of π for 75 and 275 eV, in contrast to Hartree-Fock calculations yielding 45 and 200 eV. © 1996 The American Physical Society.