Anomalous thermomechanical properties and laser-induced densification of vitreous silica

The authors studied the anomalous behaviors of vitreous silica under the combined influence of high temperature and pressure, by using molecular dynamics simulations based on a charge-transfer three-body potential. Accordingly, anomalous properties, such as the minimum in the bulk modulus at similar to 2-3 GPa and the negative thermal expansion while under pressure, are inherently connected to the ability of the glass to undergo irreversible densification. Their simulations reveal the structural features responsible for this behavior, as well as the extent to which these properties can be tailored through specific processing routes and hence create glass that is less susceptible to radiation damage. (c) 2006 American Institute of Physics.