Electron Spin Resonance of Gamma‐Ray Irradiated Single Crystals of Sodium Nitrite

Single crystals of sodium nitrite were irradiated with Co60 gamma rays of about 109 R at room temperature and studied by ESR method. The spectrum consists of a triplet and a quintet associated with different paramagnetic species; the former is believed to be NO2 and the latter N2O4—. From the analysis of the anisotropy of the hyperfine tensor the molecular plane of NO2 lies in the crystal ac plane, being different from the result obtained with irradiation at 77°K by Zeldes and Livingston. Molecular orbital of the unpaired electron of N2O4— was also calculated.