Studies in Secondary Relaxations in Glasses: Influence of Annealing on the Strengths of Relaxations.
Abstract
In view of a critique by DiMarzio of the standard thermodynamic treatment of the glass transition by Davies and Jones, a reexamination of that treatment was made, and its original conclusions reaffirmed. Examination of calorimetric data on quenched and annealed glasses and on the crystalline phase shows that a major part of the liquid 'configurational' specific heat and entropy arise from non-configurational factors, specifically a dependence on structural state (Fictive temperature) of (1) lattice vibrational frequencies, (2) anharmonicity, and (3) the numbers of molecular groups capable of participating in secondary relaxational motions. A study of the influence of annealing (as measured by the fictive temperature) on the strength of dielectric loss in glasses was studied on six molecular liquid glass-formers. A remarkable sensitivty of dielectric loss to fictive temperature was found (1-3 per cent per degree fictive). This sensitivity decreased as the temperature of measurement decreased. It was not possible to determine whether the changes in the Beta relaxation region were greater than the changes in the background loss. The thermodynamic implications of these results for the glass transition are pointed out. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA062617
Entities
People
- Martin Goldstein
Organizations
- Yeshiva University