Charge transfer satellite in Pr@ C₈₂ metallofullerene observed using resonant x-ray emission spectroscopy

Resonant x-ray emission spectroscopy (RXES) was performed on the metallofullerene Pr@ C₈₂ at the Pr L₃ absorption edge. We verify not only nearly three-electron charge transfers from the metal to the cage but also back-electron transfer observed as a charge transfer satellite. The results are compared to theoretical calculations with a single-impurity Anderson model. Theory shows that the electronic structure of endohedral atom in the cage is atomiclike. The satellite structure originates from the charge transfer, i.e., dynamical screening effect, induced by the core-hole potential in the final state rather than from the valence fluctuation of the rare-earth metal in the ground state. We also performed the RXES measurement of Pr ₂ O₃ for comparison.