PAL signature of physical ageing in chalcogenide glasses

✍ Scribed by Adam Ingram; Andrzej Kozdras; Oleh Shpotyuk; Roman Golovchak

• Book ID: 104542062
• Publisher: John Wiley and Sons
• Year: 2012
• Tongue: English
• Weight: 190 KB
• Volume: 249
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.201147584

✦ Synopsis

Abstract

Kinetics of physical ageing (PhA) far below the glass transition temperature (T~g~) is studied by positron annihilation lifetime and differential scanning calorimetry techniques for vitreous As~20~Se~80~ as typical representative of network glasses. The increased density fluctuations are shown to be responsible for the initial stage of PhA in this glass at below‐T~g~ temperatures. These fluctuations are correlated with changes in thermodynamic parameters of structural relaxation through the glass‐to‐supercooled liquid transition interval. General shrinkage, occurred during the next stage of PhA, is shown to be determined by the ability of system to release these redundant open volumes from the glass bulk through densification process of glass network.