L-2,L-3 x-ray absorption spectroscopy and multiplet calculations for KMF3 and K2NaMF6 (M = Ni, Cu) - art. no. 125123

The electronic structures of nickel and copper have been studied for KMF3 a nd K2NaMF6 compounds by a-ray absorption spectroscopy at the Ni and Cu L-2. 3 edges in order to characterize the M-F chemical bond. The spectral featur es have been interpreted based on the mixing of two ground-state configurat ions \3d(n)) +\3d(n+1)](L) under bar. Multiplet calculations were used to s imulate each spectrum in order to quantify the charge transfer from fluorin e to the transition metal yielding a 40% ground-state contribution of the 3 d(8) configuration for K2NaCuF6 and 65% of the 3d(7) configuration for K2Na NiF6.