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Hiroshi Kobayashi, Haruyuki Takahashi
Thermochimica Acta, Volume 532, March 2012
Abstract
The entropy change of intermediate-range orders (IROs) through the glass transition is discussed on the basis of the theories developed by Adam–Gibbs and Prigogine. It is estimated that the time dependence of the configurational entropy of glass is zero, but that of its vibrational entropy shows a constant decrease with the smallest change, while maintaining a constant fictive temperature and an isostructural state. It is shown that the spontaneous aging of well annealed glass shows a vibrational relaxation with a long relaxation time, while the annealing and physical aging of glass show a structural relaxation with a short relaxation time. The results indicate that the volume of glass decreases at a constant time rate through spontaneous aging at a constant temperature. It is emphasized that the existence of the constant configurational entropy below the glass transition temperature is the basic feature of glass forming. The nanoorder-size of the IROs in glass determines the residual entropy. The time symmetry in glass is spontaneously violated. The glass transition is a nano-emergence through the abrupt decrease in the fluctuations in the supercooled liquid state.
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