ENDOR study of RbCl: S2–

Abstract

A recent EPR study revealed an exceptionally well resolved superhyperfine structure in the spectrum of RbCl : S₂^– for some specific orientations of the magnetic field. In this work a complete angular variation of two sets of ⁸⁵Rb and ⁸⁷Rb ENDOR transitions is presented. The corresponding hyperfine and nuclear quadrupole coupling tensors were determined. The orientation of the principal axes of these tensors is in agreement with the overall D_2h symmetry of the S₂^– ion in the crystal. The ENDOR results can be explained only by assuming a monovacancy model, i.e. S₂^– replacing a single Cl^–. The earlier EPR results are in perfect agreement with the present ENDOR analysis.