Electronic structure ofCeAg2Ge2studied by resonant photoemission spectroscopy

Abstract

The electronic structure of ${\text{CeAg}}_{2}{\text{Ge}}_{2}$ single crystal has been investigated by using valence-band photoemission at different photon energies ranging from 110 to 150 eV. Resonant photoemission has been observed near the $4d$ threshold of Ce at 121 eV. The constant initial-state spectra shows two photoemission features having $4f$ character near the Fermi level at $\ensuremath{-}0.4$ and $\ensuremath{-}1.7\text{ }\text{eV}$ which exhibits Fano-type sharp resonance character. The experimental spectra have been interpreted with the help of calculations based on full-potential linearized augmented plane-wave method using density-functional theory. Excellent agreement has been obtained between the theory and the experiment. The origin of the feature near to Fermi level is related to the $\text{Ce}\text{ }4f$ states and the feature at $\ensuremath{-}1.7\text{ }\text{eV}$ is related to the strong hybridization between the $\text{Ce}\text{ }4f$ and $5d$, $\text{Ag}\text{ }4d$ and $\text{Ge}\text{ }4p$ states.