Details

Autor(en) / Beteiligte

• Bove, L.
• Dreyfus, C.
• Polian, A.
• Bonello, B.
• Malfanti, I.
• Taschin, A.
• Torre, R.
• Pick, R. M.

Titel

The low frequency dynamics of supercooled LiBr, 6H2O

Ist Teil von

• The Journal of chemical physics, 2011-01, Vol.134 (3), p.034514-034514

Ort / Verlag

United States

Erscheinungsjahr

2011

Quelle

美国小型学会期刊集（AIP Scitation平台）

Beschreibungen/Notizen

• We present results of a series of experiments performed on LiBr, 6H20 from room temperature down to 172 K ≈ 1.2T g. These ultrasound, Brillouin and depolarized light scattering, and transient grating experiments show that, above 215 K, this solution behaves like supercooled water: its zero frequency sound velocity C 0 continuously decreases with decreasing temperature, and the reorientational dynamics of the water molecules can be directly detected at some temperatures of this domain. Conversely, below 215 K, a new regime sets in, where the apparent C 0 is practically temperature independent and where a β, Arrenhius like, relaxation process coexists with the usual, Vogel–Fulcher like, α relaxation process of the supercooled liquid. These results are similar to those recently obtained in LiCl, 6H2O. The onset of the new regime is possibly due to an increase of the interaction of the water molecules with a neighboring Li+ ion when lowering the temperature. We also compare our results with published dielectric data on water solutions of glass forming polyalcohols. Some of them present a low temperature splitting of their relaxation time similar to what is found in LiBr, 6H2O.