Dynamics in a nonfragile glass-forming liquid
- Univ. de Rennes (France). Groupe Matiere Condensee et Materiaux; and others
The dynamics of Na{sub 0.5}Li{sub 0.5}PO{sub 3} (T{sub g} = 515 K, T{sub m} = 749 K) a non fragile glass forming liquid has been investigated over a large temperature range (300--1,000 K) and in a wide energy window using various experimental techniques. The susceptibility spectra obtained by coherent neutron scattering and depolarized light scattering between 1 and 10{sup 4} GHz show mainly two contributions: a low frequency vibrational peak, the so-called Boson peak show mainly two contributions: a low frequency vibrational peak, the so-called Boson peak and quasielectric component, referred to the {beta}{sub fast} process in the mode coupling theory (MCT). The data are discussed in relation to the mode coupling theory for the liquid glass transition. In particular, the temperature evolution of the susceptibility height in the {beta}{sub fast} region is compatible with a crossover temperature T{sub c} {approximately} 620 K which is also deduced from a power law temperature dependence of the structural relaxation timescale. As a secondary {beta}{sub slow} process, observed by {sup 31}P NMR, decouples from the structural relaxation timescale also below 600 K, a real change in the dynamics seems to occur around T{sub c} {approximately} 620 K = 1.2 T{sub g} in this non fragile glass forming liquid.
- OSTI ID:
- 580867
- Report Number(s):
- CONF-961202--; ISBN 1-55899-359-2
- Country of Publication:
- United States
- Language:
- English
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