Efficiency of paramagnetic center formation in alkali nitrates with different crystalline structures

Abstract

The accumulation of paramagnetic centers in alkali nitrate crystals irradiated at 77 K and their thermal stability have been studied. The difference in radiation chemical yields of the hole and electron paramagnetic centers registered by means of ESR spectra are assumed to be connected with the formation of the product due to the localization of the spatially correlated electron pairs on neighboring anion sites. A similar product must be formed in irradiated inorganic alkali salts where anion layers are separated by cation layers thus resulting a greater initial radiation chemical yield of the hole paramagnetic centers as compared to that of the electron centers. In the salts with a three-dimensional frame of anions the formation yields are quite opposite. Besides paramagnetic centers due to anion dissociation products are registered in these salts at 77 K even at low absorbed doses.