Date of Award
Doctor of Philosophy
Physics and Astronomy
A temperature dependent photoemission study was performed on cerium metal to understand the role of the 4f electron in the isostructural (gamma)-(alpha) phase transition. The partial yield spectra clearly indicate a 4f occupation number of one for both phases. The observed differences in the partial yield spectra consist mainly of a broadening of the multiplet structure. This broadening has been interpreted in terms of a slight delocalization of the 4f electron in transforming from the high volume (gamma) phase to the more compact (alpha) phase;The energy distribution curves show two 4f related features in the valence band spectra. The feature located at -2.0 eV has been assigned to a direct emission of the 4f electron. The second feature is located near the Fermi level and has been attributed to a screening process involving the 5d valence electrons. Upon transforming to (alpha)-Ce, the screened feature increases in intensity at the expense of the direct feature. This has been interpreted as a decrease in the 4f-5d Coulomb repulsion;From the two complementary experiments, we conclude that both phases contain a single 4f electron that becomes slightly delocalized in the (alpha)-phase;('1)DOE Report IS-T-1037. This work was performed under ContractNo. W-7405-Eng-82 with the U.S. Department of Energy.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
David Michael Wieliczka
Wieliczka, David Michael, "A photoemission study of the 4f character in gamma and alpha cerium " (1982). Retrospective Theses and Dissertations. 8397.