Electron Spin Resonance Studies On gamma-Irradiated KmnO4

摘要

Electron spin resonance (ESR) studies were carried out on the radicals produced by the gamma-irradiation of single crystals of KMnO4. A crystal holder has been designed which allows an accurate orientation of the crystal. Analysis of the data yields at least two paramagnetic species. The first radical is produced by room temperature irradiation and gives a single line for each of two inequivalent magnetic sites. There is no resolvable hyperfine structure. The spectrum is tentatively assigned to the MnO2 or the MnO4 radical. The second radical is produced by irradiation at 77K and the spectrum disappears irreversibly at slightly higher temperatures. This spectrum is assigned to the MnO4(-2) radical. The relationship of the radicals observed to the effect of high energy radiation on the decomposition of KMnO4 in the light of current solid state theory is discussed. (Author)