We suggest a model of the atomic and electronic processes responsible for the so-called 110 and 325 °C thermoluminescence (TL) peaks, including predose behavior, and for the room temperature optically stimulated luminescence (OSL) of quartz. Our model is based on defects and defect processes typical of those known from many previous studies of quartz. It explains the experimental observations that the two TL peaks and OSL are correlated with respect to the effects of thermal annealing and photoexcitation after irradiation. The model indicates that the energy for the two TL peaks and OSL is all stored by the same defect pairs. These defect pairs comprise [AlO4]− and [X/M+]+ generated by a radiolytic reaction [AlO4/M+]0→[AlO4]−+M+. Here [AlO4]− is an Al impurity center substituting a Si atom, M+ is an alkali ion, [X/M+] is M+ stabilized by a defect denoted by X and [AlO4/M+]0 is an [AlO4]− center charge compensated by M+. Even though the 110 and 325 °C TL peaks and OSL arise from the same defect pairs, they should emit different luminescence because they arise through different mechanisms: the 325 °C TL peak through the migration of M+, and the OSL through the migration of holes. The 110 °C TL peak is ascribed to the electron–hole recombination at the [AlO4]− centers. According to the model, the TL at 110 and 325 °C and OSL luminesce at different wavelengths.
We present a model of the predose effect of thermoluminescence in crystalline quartz in terms of known impurities and defect processes. . This excitation-induced ionic process is a new feature, in addition to the simple carrier redistribution processes usually assumed, and is consistent with a number of experiments. The test dose detects [X M + ], which is present in a concentration within the dynamic range of thermoluminescence measurements. Our model enables us to understand the enhanced sensitivity of the predose method, which has been widely used in archaeological and accident dosimetry, and to link it to established impurity and defect centres in α-quartz.
S
Combination of the routine approaches of thermoluminescence dating, the fine‐grain and inclusion methods, allows an age to be determined that is independent of knowledge of the environmental dose‐rate. This socalled subtraction technique is exampled by several terracottas of museum origin and some pottery collected from archaeological contexts without associated burial media. Age determination is estimated to have an accuracy of around ± 12%, in favourable conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.