COMPARISON OF ELECTRON-NUCLEAR DOUBLE RESONANCE SPECTRA OF CE3+-H- AND CE3+-F-IN CALCIUM FLUORIDE

From electron-nuclear double resonance spectra we deduce that the tetragonal EPR spectra of rare-earth ions arise from F- or H- ions located interstitially in the adjacent cube. The hyperfine tensor is similar in both cases. The anisotropy and the isotropic part of the hyperfine interaction must result mainly from the Ce3+ configurations. Simple linear combination of atomic orbitals theory would yield very different values for H- and F- ions. Admixture from three-electron configurations or from the odd crystal field may explain the results. © 1969 The American Physical Society.