Formation of Radiation-Induced Defects in Glasses of the Copper-Arsenic-Selenium System

Abstract

The defects generated under exposure to gamma and electron radiation at a temperature of 77 K in glasses lying along the Cu 2 Se-As 2 Se 3 quasi-binary join of the Cu-As-Se system are studied by the electron paramagnetic resonance (EPR) method. It is shown that the introduction of copper even in small amounts leads to both the disappearance of defects typical of As 2 Se 3 and the formation of new defects associated with copper. The structure of the latter defects is retained over the entire composition region and under electron irradiation. The dependence of the defect concentration on the Cu 2 Se content in the glass reaches saturation at high copper concentrations. Manganese impurities compensate for dangling bonds of defects and, thus, decrease their con- centration. Exposure to gamma irradiation brings about the formation of NO 2 paramagnetic molecules from nitrogen and oxygen uncontrollable impurities contained in some glasses. Under electron irradiation, these paramagnetic molecules transform into complex defects involving two nitrogen atoms located in nonequivalent positions.