Radiophotoluminescent Centers in Silver-Activated Phosphate Glass

Abstract

ESR studies of radiophotoluminescence (RPL) centers in silver-activated phosphate glass were performed after the glasses had been γ-irradiated at 77°K. It is shown that the silver ions act as traps for both electrons and positive holes. By the separate formation of electron-trapped silver centers and hole-trapped silver center, it was verified that all these silver centers act as RPL centers. It was found that a positive hole in PO₄ tetrahedron is transfered to Ag⁺ ion and this process is the main reason of RPL build-up. Stabilization phenomenon of RPL centers was found. It was found that alkali and or silver ion migration is necessary for stabilization. The reason why RPL in these glasses has high stability and builds-up after γ-irradiation was clarified. The resonances which are considered due to exchange coupled pairs, triads and higher aggregates of electron-trapped silver centers were found.