Role of multielectron excitations in the L3 XANES of Pd

High resolution L₃ and L₂ XANES (X-ray absorption near edge structure) spectra of Pd metal have been measured at the Frascati synchrotron radiation facility. The L₃ XANES shows an intense 2p → 4d “white line” while at the L₂ a weaker structure appears. A good agreement between L₃ XANES and the one-electron theory of Muller et al. has been found. All the possible final state effects due to the relaxation of the many body system are discussed. No many body effects have been seen on the “white line” at threshold. The intensity ratio between L₃ and L₂ absorption is 2.1 in the high energy range of XANES and it is 2.7 at the white line maximum. A weak broad band extending up to 13 eV and centered at ～ 6 eV above the Fermi level, appearing in the L₃-L₂ difference spectrum, could be tentatively assigned either to the only possible very weak multielectron excitation present in XANES of Pd i.e. the “two hole-two electron” excited state or to the prevalence of the $\text{j}\text{=}\text{5}\text{2}$ total angular momentum for electrons in the 5sp band, hybridized with the 4d band, up to 3 eV above the Fermi level.