Electronic Structure Of EuCu2Ge2 Studied By Resonant Photoemission Spectroscopy.

The electronic structure of EuCu₂Ge₂ single crystal has been investigated by valence band photoemission at different photon energies ranging from 134 eV to 170 eV. Eu exists in both Eu²⁺ and Eu³⁺ valence states in this compound and its origin is related to the intra-ion transition due to the fast fluctuation of an electron between the localized 4f level and the conduction band. Resonant photoemission features has been observed near the 4d threshold of Eu at 141 eV for Eu²⁺ states and at 145 eV for Eu³⁺ states. The constant initial state spectra for Eu²⁺ and Eu³⁺ states at -1.5 eV and -7.5 eV exhibits Fano-like sharp resonance profile having 4f character. Multiplet structures have been observed for the Eu³⁺ state. [ABSTRACT FROM AUTHOR]