Electron-spin-resonance investigation of chromium ions in NaCl

The electron-spin-resonance spectrum of Cr ions in NaCl is examined. After x irradiation, a spectrum is identified belonging to ions of Cr+(3d5) in sites of cubic symmetry. The g value, fine structure, and hyperfine splitting are determined, and compared with the corresponding values in the case of NaF. In addition, the unirradiated crystals yield a spectrum attributed to Cr2+(3d4) ions in noncubic sites of several types. © 1965 The American Physical Society.