Glass Relaxation Kinetics. Dynamic Activation Energy Assumption.
Abstract
The assumption was made that the activation energy of a relaxation process chan change slightly (<4%) as the system relaxes. The empirical consequences of such an assumption are as follows: the normally exponential decay function becomes more gradual or broadened in precisely the manner observed for glass and polymer relaxations; the well-known fractional-exponential expression for the response function is easily obtained; a well-defined temperature dependence is predicted for the width parameter b, which is in excellent agreement with recent measurements on B2O3 glass; and conventional finite-amplitude (nonlinear) correction terms can be introduced in a more unified manner than was previously possible. A simple physical justification for this time-dependent activation energy is that the structural units that relax later encounter a somewhat larger activation barrier than do the units that relax first. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 17, 1978
- Accession Number
- ADA061790
Entities
People
- Jacek Jarzynski
- Robert D. Corsaro
Organizations
- United States Naval Research Laboratory