Studies of crystallization of SiO2-glass by positron annihilation
Studies of crystallization of SiO2-glass by positron annihilation
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SiO2-玻璃正电子湮灭结晶化的研究
DOI：
10.1007/bf02056399
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发表时间：
1996
影响因子：
1.6
通讯作者：
K. Maier
中科院分区：
文献类型：
--
作者：
C. Hugenschmidt;U. Holzwarth;M. Jansen;S. Kohn;K. Maier
通过正电子寿命光谱以及使用 X 射线衍射和核磁共振 (NMR) 的相关研究对石英玻璃的结晶进行了研究。为此，在 700 °C 至 1600 °C 的范围内进行等温和等时热处理。寿命光谱由两个寿命分量进行分析。短寿命（200 ps）的减少归因于结晶相体积分数的增加。长寿命 (1000 ps) 与空腔中 Theo-Ps 态的拾取湮灭有关。随着晶核开始形成，长寿命增加，这是通过晶相和非晶基体之间界面处空腔的扩展来解释的。
The crystallization of silica glass has been studied by positron lifetime spectroscopy and accompanying investigations using X-ray diffraction and nuclear magnetic resonance (NMR). To this end isothermal and isochronal heat treatments were performed in the range from 700 °C up to 1600 °C. The lifetime spectra are analyzed by two lifetime components. The decrease of the short lifetime (200 ps) is attributed to the increasing volume fraction of the crystalline phase. The long lifetime (1000 ps) is related with the pick-off annihilation of theo-Ps states in cavities.With starting formation of crystallization nuclei the long lifetime increases which is explained by expanding cavities at the interface between crystalline phase and amorphous matrix.