Exchange and Crystal Field Effects in the ESR spectra of Eu$^{2+}$ in LaB$_{6}$

POSTER

Abstract

The Electron Spin Resonance (ESR) spectra of Eu$^{2+}$ (4$f ^{7}$, $S $= 7/2) in LaB$_{6}$ single crystal show a single Dysonian resonance for the localized Eu$^{2+}$ magnetic moments. It is shown that the Eu$^{2+}$ ions are covalent exchange coupled to the (B) 2\textit{p - like }host conduction electrons. The anisotropy of the ESR spectra is interpreted in terms of an averaged positive fourth order cubic crystal field parameter.

*Supported by FAPESP, CNPq, NSF-DMR, 0102235 and US DOE.

Authors

  • Carlos Rettori

    • Instituto de F\'isica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil

  • Jose Duque

    • Instituto de F\'isica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil

  • Ricardo Urbano

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545

  • Pablo Venegas

    • Dpto. de F\'isica, Universidade Estadual Paulista - Unesp, CP 473, 17033-360, Bauru, SP, Brazil

  • Pascoal Pagliuso

    • Instituto de F\'isica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil

  • Zachary Fisk

    • Department of Physics, University of California, Davis, CA 95616, U.S.A.

  • Saul Oseroff

    • San Diego State University, San Diego, CA, 92182, U.S.A.