Thermally-induced crystallization behaviour of 80GeSe₂-20Ga₂Se₃ glass as probed by combined X-ray diffraction and PAL spectroscopy

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• 作者：O. Shpotyuk ; L. Calvez ; E. Petracovschi ; H. Klym ; A. Ingram ; P. Demchenko
• 关键词：Chalcogenide glass ; Crystallization ; Positron annihilation ; Trapping ; Annealing
• 刊名：Journal of Alloys and Compounds
• 出版年：2014
• 出版时间：5 January, 2014
• 年：2014
• 卷：582
• 期：Complete
• 页码：323-327
• 全文大小：483 K

文摘

Crystallization behaviour of 80GeSe₂-20Ga₂Se₃ glass caused by thermal annealing at 380 ¡ãC for 10, 25 and 50 h are studied using X-ray diffraction and positron annihilation lifetime spectroscopy. It is shown that the structural changes caused by crystallization can be adequately described by positron trapping modes determined within two-state model. The observed changes in defect-related component in the fit of experimental positron lifetime spectra for annealed glasses testifies in a favour of structural fragmentation of larger free volume entities into smaller ones with preceding nucleation in the initial stage of thermal annealing. Because of strong deviation in defect-free bulk positron lifetime from corresponding additive values proper to boundary constituents, the studied glasses cannot be considered as typical representatives of pseudo-binary cut-section.