Photoionization-cross-section studies of atomic and final-state effects on the Pb 5 d core levels using synchrotron radiation

Using monochromatized synchrotron radiation as the light source, the Pd-5 d cross sections in Pb metal and the 5 d52:5 d32 branching ratios in Pb metal, PbS, PbSe, and PbCl2 have been studied from 22- to 90-eV photon energies. Constant-initial-state (CIS) spectra for Pb metal from 22 to 40 eV photon energies allow a direct comparison of the 5 d52 and 5 d32 cross sections. Superimposed on a smooth curve due to atomiclike behavior, the d52 and d32 CIS curves show differing structure that is probably related to transitions from the d levels to p-like states in the conduction band. The area ratios are chemically sensitive, and at higher photon energies contain structure which is probably due to scattering from neighboring atoms as seen in extended x-ray absorption fine structure. © 1978 The American Physical Society.