Glass transition in an isostatically compressed calcium metaphosphate glass

The authors report an ambient-pressure differential scanning calorimetric study of a calcium metaphosphate glass that has been isostatically compressed slightly above its glass transition temperature and was frozen-in under pressure. It is shown that the enthalpy overshoot of the calorimetric glass transition is enhanced by this treatment. This enhancement is associated with a decrease in the apparent fictive temperature T-fA that is determined using the enthalpy-matching approach. The origin of this correlation is discussed. (c) 2007 American Institute of Physics.