Chapter 66 Photoemission of Ce and its compounds

Abstract

Publisher Summary The chapter discusses photoemission of Ce and its compounds. With photoemission, particularly with synchrotron radiation photoemission, it is now possible to extract information about the nature of the electronic states themselves, including their spin and angular momentum character, their degree of localization or hybridization, their wave function symmetry, and the detailed energy band structure in the form of energy vs. momentum or E(k). Information about the empty states can also be gained from angle integrated or angle resolved photoemission or through core level excitation spectra near threshold. The chapter describes those techniques, especially those utilizing synchrotron radiation as the photon source. The chapter surveys photoelectron spectroscopy results for metallic and semiconducting Ce compounds, presenting results for La and Pr when possible to aid in the interpretation of the 4f character, and conclude with a discussion of Ce oxides and oxidation. The discussion includes photoemission studies of the 4d core levels of Ce because these levels are usually within the range of excitation of the instrumentation used to obtain valence band spectra (binding energy ∼ 100 eV) and because their spectra are complementary to direct valence band and 4f electron studies.