Fragility and compressibility at the glass transition

Abstract

Isothermal compressibilities and Brillouin sound velocities from the literature allow to separate the compressibility at the glass transition into a high-frequency vibrational and a low-frequency relaxational part. Their ratio shows the linear fragility relation discovered by x-ray Brillouin scattering [1], though the data bend away from the line at higher fragilities. Using the concept of constrained degrees of freedom, one can show that the vibrational part follows the fragility-independent Lindemann criterion; the fragility dependence seems to stem from the relaxational part. The physical meaning of this finding is discussed. [1] T. Scopigno, G. Ruocco, F. Sette and G. Monaco, Science 302, 849 (2003)

4 pages, 2 figures, 2 tables, 33 references. Slightly changed after refereeing

References in corpus (2)

• Is the Fragility of a Liquid Embedded in the Properties of its Glass?
• High frequency acoustic modes in vitreous Beryllium Fluoride probed by inelastic X-ray scattering

Cited by in corpus (20)

• Relaxation and physical aging in network glasses: a review
• Why liquids are fragile
• Universal divergenceless scaling between structural relaxation and caged dynamics in glass-forming systems
• Probing equilibrium glass flow up to exapoise viscosities
• A thermodynamic approach to the fragility of glass-forming polymers
• Effect of Chemical Structure on the Isobaric and Isochoric Fragility in Polychlorinated Biphenyls
• Connection between slow and fast dynamics of molecular liquids around the glass transition
• In situ measurements of density fluctuations and compressibility in silica glass as a function of temperature and thermal history
• Density scaling of the diffusion coefficient at various pressures in viscous liquids
• Ultrafast spherulitic crystal growth as a stress-induced phenomenon specific of fragile glass-formers
• Poisson ratio and excess low-frequency vibrational states in glasses
• Non-gaussian effects in the cage dynamics of polymers
• Ergodicity breaking in strong and network-forming glassy system
• Cage effect in supercooled molecular liquids: local anisotropies and collective solid-like response
• Solidity of viscous liquids. V. Long-wavelength dominance of the dynamics
• A new way to evaluate x-ray Brillouin scattering data
• Cage rattling does not correlate with the local geometry in molecular liquids
• High pressure specific heat spectroscopy reveals simple relaxation behavior of glass forming molecular liquid
• Fragility and elastic behavior of a supercooled liquid
• Inelastic x-ray scattering reveals the ergodic to nonergodic transition of salol, a liquid with local order