Inorganic radicals: Electron spin resonance studies of radiation damage in some oxygen compounds.

The electron spin resonance spectra of the radicals produced by irradiation of a variety of oxysalts of phosphorus and selenium have been studied at 77°K and 300°K. A number of new radicals and radical ions, including PO-24, PO3, SeO-2, SeO-3 and SeO-4, have been identified and these results have demonstrated that much structural information can be obtained from the spectra of powdered samples in which the radicals are randomly oriented. The results of a special study of hydrogen atoms trapped in many irradiated phosphates are presented. In some of these materials the hydrogen atoms remain trapped at temperatures greater than 400°K. Because of the many anomalies revealed by earlier studies a fresh investigation of the electron spin resonance of the radicals trapped in irradiated ice at low temperatures has been started. The preliminary results of these investigations are presented. Some of the anomalies are satisfactorily resolved by a new interpretation of the spectrum.