Cu L 3 x-ray absorption of formally trivalent Cu compounds

Abstract

The Cu L 3 X-ray Absorption Spectra (XAS) of formally trivalent Cu compounds NaCuO 2, La 2Li 0.5Cu 0.5O 4, and KCu(III)(biuret) 2 have been measured. The spectra of trivalent systems exhibit two white lines. The low energy white line is found to be at about the same energy, between 930.9 eV and 931.2 eV on the contrary the high energy white line in the range between 933 eV and 933.9 eV is dependent on the chemical bond and it is assigned to the 3d 9 L initial state. The joint analysis of the Cu 2p XPS and XAS spectra of NaCuO 2 shows that both white lines are below the XPS main line 3d 10 L 2 and the energy separation between the XAS(3d 10 L) and the XPS (3d 10 L 2) final state Δ = 1.7 ± 0.2eV is related to the energy for excitation of a ligand hole.