LIII-EDGE SPECTROSCOPY ON CERIUM-BASED INTERMEDIATE-VALENT COMPOUNDS

In this paper, the L(III)-edge spectroscopy in cerium-based compounds is discussed in the frame-work of a single-impurity model. A few years ago, Gunnarsson and Schonhammer developed a model to describe photoemission in such systems. This model neglects the interaction between the photoelectron and the remaining system and then is not appropriate for L(III) absorption. More recently, Jo and Kotani proposed an approach to describe the L(III) edge of cerium oxide that accounts for the Coulomb interaction between the photoelectron, the f electron, and the core hole. I present a modification of this model by introducing a hybridization term between the photoelectron and the conduction states. A better agreement with experiment is then obtained for intermetallic compounds. Moreover, the phenomenological approach of the L(III) edges used by most experimentalists is discussed.