Thermodynamic nature of the glass transition interval

Quenching a glass-forming liquid as a kinetic factor, determines the formation of thermodynamic conditions that are characteristic of a solid glass and a system within the glass transition interval. In a glass-forming liquid, the excess volume is the reason for the existence of negative pressure that changes within the glass transition interval and becomes 'frozen' upon the transformation of a non-equilibrium liquid into a glass. Excess volume and negative pressure are the features of a glass transition that occurs either with quenching or with an increase in the external pressure. Negative pressure which is 'frozen' in solid glasses causes their anomalous thermal expansion in the vicinity of the absolute zero temperatures. (C) 2004 Elsevier B.V. All rights reserved.