E.S.R. Investigation of 3d9 Ions in Alkali-Halides

Cu 2+ in NaCl, LiCl and NaF, and Ni + in NaCl, most of which were produced from Cu + and Ni 2+ by X-ray irradiation were studied by the e.s.r. All of Cu 2+ had elongated tetragonal surroundings, while Ni + had compressed ones. In NaCl: Cu 2+ , the optical dichroism along a cube edge was detected at 5 K corresponding to the Jahn-Teller distortion. From the observed super hyperfine structure of surrounding nuclei the amounts of covalency, f s and f σ were estimated as 0.77 to 0.89% and 7.9 to 12% in the chlorides, respectively. In the case of NaCl: Cu 2+ doped as divalent states, sharp anisotropic spectra without the hyperfine structure due to Cu nucleus were observed, which are presumably due to coagulated ions.