对光热折变(Photo-thermal-refractive, PTR)玻璃在总剂量分别为0.35、1、10及100 kGy的γ射线下辐照, 并进行热退火处理, 采用吸收光谱、光致发光光谱及EPR电子顺磁共振谱研究了光热折变玻璃在γ射线辐照下的辐照机理。研究结果表明, γ辐照后的PTR玻璃在可见波段的吸收主要由银原子Ag⁰、银分子簇Ag₂、银分子簇Ag₃、银纳米颗粒Ag_m⁰及非桥氧空穴中心HC₁及HC₂引起; 在不同剂量γ射线辐照下, 玻璃基质中的变价离子(Ag⁺、Ce³⁺)价态先发生变化, 同时玻璃基质中的非桥氧键发生电离, 形成了非桥氧空穴型缺陷中心HC₁、HC₂。进一步增加辐照剂量, 产生了银的分子簇Ag₂和Ag₃; 同时玻璃基质中非桥氧空穴中心HC₂的浓度增大, 导致在639 nm附近的吸收增强。分别在不同温度下对辐照后的PTR玻璃进行相同时间的热处理及在低于T_g(玻璃转变温度)的温度下进行不同时间的热处理, 观察到250 ℃退火后PTR玻璃中HC₁及HC₂缺陷中心发生漂白; 并在430 ℃退火后出现了银纳米颗粒的吸收峰, 该吸收峰随退火时间的延长发生了红移及展宽。

Photo-thermal-refractive (PTR) glass was irradiated with γ-ray at the total dose of 0.35, 1, 10 and 100 kGy, respectively, and then annealed. Irradiation mechanism of the photo-thermal-refractive glass was studied by absorption spectroscope, luminescence spectroscope and electron paramagnetic resonance. The results showed that the absorption of the γ-irradiated PTR glass in the visible light was mainly caused by the Ag⁰, silver molecular clusters Ag₂, Ag₃, silver nanoparticles Ag_m⁰, and non-bridge oxygen hole center HC₁ and HC₂. Under different doses of γ-ray irradiation, valence state of the ions (Ag⁺, Ce³⁺) in the glass matrix changed. At the same time, non-bridged oxygen bonds in the glass matrix broke, generating non-bridged oxygen hole defects HC₁, HC₂ and Ag⁰. With the increase of the radiation dose, silver molecular clusters Ag₂ and Ag₃ generated, and the concentration of HC₂ center in the glass matrix increased, resulting in enhanced absorption near 639 nm. After being irradiated and annealed at 250 ℃, HC₁ and HC₂ defect centers was bleached. Silver molecules appeared after annealing at 430 ℃, of which absorption peak had a redshift and was broadened with the increase of annealing duration.