Source-trap characterization of thermally transferred OSL in quartz
Source-trap characterization of thermally transferred OSL in quartz
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石英中热转移 OSL 的源-阱表征
DOI：
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发表时间：
2011
期刊：
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通讯作者：
A. Lang
中科院分区：
文献类型：
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作者：
Z. Shen;B. Mauz;A. Lang
石英的热传递光激发发光（TT-OSL）是在将先前光学归零的石英加热到擦除OSL电子陷阱的温度以下后测量的低强度OSL。我们通过研究不同温度下光学漂白引起的TT-OSL和热释光（TL）的变化以及重复的TT-OSL测量来确定有助于TT-OSL的源阱，并使用Hoogenstraaten方法量化源阱参数。我们发现单传递机制和双传递机制都对TT-OSL的产生有贡献。当样品被加热到300°C 10 s以诱导热传递时，确定了三个源陷阱。第一个对应于~ 200°C的TL峰。它在光学漂白过程中捕获电子，并在随后的加热过程中释放这些电荷。它提供了产生TT-OSL的电子的~ 10%。第二个陷阱对应于290-300°C的TL峰，并通过单一转移机制为TT-OSL提供~ 80%的电子。该电子阱深度为1.34±0.05 eV，频率因子约为1011 s−1。它在10°C下的平均寿命为0.24 Ma。第三个陷阱对应于~ 380°C的TL峰，并通过单一转移机制为TT-OSL提供~ 10%的电子。其深度为1.66±0.07 eV，频率因子约为1012 s−1。为了验证所使用的技术，我们还确定了快速组分OSL陷阱的参数，并获得了与公布值一致的结果。最重要的是，我们的结果表明，主要TT-OSL源圈闭的相对较短的寿命限制了使用TT-OSL来延长石英OSL测年年龄范围的可能性，正如许多作者所建议的那样。
Thermally transferred optically stimulated luminescence (TT-OSL) of quartz is the low intensity OSL measured after heating a previously optically zeroed quartz to temperatures below that erasing the OSL electron trap. We identify the source traps contributing to TT-OSL by studying the changes in TT-OSL and thermoluminescence (TL) caused by optical bleaching at various temperatures and by repeated TT-OSL measurements, and quantify source-trap parameters using the Hoogenstraaten method. We find that both the single transfer mechanism and the double transfer mechanism are contributing to TT-OSL production. Three source traps are identified when the samples are heated to 300 °C for 10 s to induce the thermal transfer. The first one corresponds to a TL peak at ∼200 °C. It captures electrons during the optical bleaching and releases these charges during subsequent heating. It provides ∼10% of the electrons that give rise to TT-OSL. The second trap corresponds to a TL peak at 290–300 °C and provides ∼80% of the electrons for TT-OSL through the single transfer mechanism. This electron trap has a depth of 1.34 ± 0.05 eV and a frequency factor in the order of 1011 s−1. It has a mean lifetime of 0.24 Ma at 10 °C. The third trap corresponds to a TL peak at ∼380 °C and provides ∼10% electrons for TT-OSL through the single transfer mechanism. It has a depth of 1.66 ± 0.07 eV and a frequency factor in the order of 1012 s−1. To validate the techniques used we also determined the parameters of the fast component OSL trap and received results consistent with published values. Most importantly, our results show that the relatively short lifetime of the main TT-OSL source trap limits possibilities of using TT-OSL to extend the age range of quartz OSL dating, as has been suggested by various authors.