A Nonlinear Structural Relaxation Model for the Glassy State: Application to B2O3

Traditionally fictive temperature has been used to characterize the structural state of glasses. Since this concept has certain shortcomings, use of a second thermodynamic ordering parameter along with fictive temperature in a nonlinear model is proposed. This model is applied to refractive index relaxation data, from the literature, for B2O3 glass. Data were considered as the refractive index relaxed to a new equilibrium temperature from both higher and lower fictive temperatures.