Radiation effects in a glass-ceramic

Electron spin resonance (ESR) and optical absorption techniques have been used to investigate the effects of ionizing radiation in a glass-ceramic. Samples of Zerodur were electron-irradiated either at 77 K or at room temperature, and five distinct ESR spectra and two optical absorption peaks were observed. Three of the ESR centers are holelike and two are electronlike. One of the electron centers, represented by a narrow ESR line at g = 1.9980, is easily produced by the 77-K irradiations and is suggested to be an oxygen-vacancy-related defect. The other electron center has a broad ESR line at g = 1.93 and is dominant after the room-temperature irradiations. This latter defect is created when electrons are trapped at high-valence cations such as zirconium or titanium, thus forming either Zr3+ or Ti3+ ions. These heavy-metal-ion electron centers decay in the 100–300 ° C range.