RELATION BETWEEN COPPER L X-RAY-FLUORESCENCE AND 2P X-RAY PHOTOELECTRON SPECTROSCOPIES

Lalpha1,2,beta1(L3,2-V) x-ray fluorescence spectra (XRF) and 2P1/2,3/2 x-ray photoelectron spectra (XPS) of various copper compounds are measured. It is found that the intensity of the high-energy hump of the Cu Lalpha XRF has a correlation with that of the high-binding-energy satellite (corresponding to the poorly screened 2p-1 final state) of the Cu2P3/2 XPS. While both the poorly screened peak in the 2P3/2 XPS and the high-energy hump in the Lalpha XRF are strong for ionic divalent copper compounds, both of them are very weak for covalent divalent copper compounds, and they exist for neither monovalent nor metallic copper compounds. It was believed that the high-energy hump of the Lalpha XRF originated from the electron transition between L3M4,5-M4,5(2) multiple-hole states, where the L3M4,5 double-hole state was created by the L1,2L3M4,5. Coster-Kronig transition prior to the x-ray transition. In this context, the Lalpha line shape, except for the high-energy hump, was believed to represent the Cu 3d electron density of states (DOS). Our results, however, exclude the possibility of the multiple vacancy satellite 2p(5)3d8 --> 3d7 for the origin of the high-energy hump of the Lalpha XRF of the divalent copper compounds. It is concluded that the major portion of the high-energy hump of the Lalpha XRF of the divalent copper compounds is due to the transition between the poorly screened states 2p(5)3d9 --> 3d8. Consequently, it is also concluded that the Lalpha line shape does not directly represent the 3d DOS but the high-energy hump hidden in the Lalpha main line represents the 3d DOS. We also conclude that the Lalpha main line originates from the charge-transfer effect.