ABSTRACT
At temperatures sufficiently far above the temperature range where the glass transition occurs, the atomic or molecular entities of the system move at sufficiently rapid rates that the system achieves equilibrium on reasonable time scales. With decreasing temperature, glass-forming liquids exhibit increasingly slow dynamics in the absence of the formation of long-range order. The relaxation times increase in a non-Arrhenius manner with decreasing temperature, and, eventually, the rate of cooling exceeds the ability of the system to reach equilibrium on a reasonable time-scale. Under such circumstances, the system is nonergodic. It is considered to be frozen on the time scale of observation, denoting glass formation.
