The Boson peak in confined water: An experimental investigation of the liquid-liquid phase transition hypothesis

• Main Authors: Mallamace, Francesco (Contributor), Corsaro, Carmelo (Author), Mallamace, Domenico (Author), Wang, Zhe (Contributor), Chen, Sow-Hsin (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Nuclear Science and Engineering (Contributor)
• Format: Article
• Language: English
• Published: Springer Nature, 2016-06-09T16:24:11Z.
• Subjects: Article
• Online Access: Get fulltext

The Boson peak (BP) of deeply cooled confined water is studied by using inelastic neutron scattering (INS) in a large interval of the (P, T) phase plane. By taking into account the different behavior of such a collective vibrational mode in both strong and fragile glasses as well as in glass-forming materials, we were able to determine the Widom line that characterizes supercooled bulk water within the frame of the liquid-liquid phase transition (LLPT) hypothesis. The peak frequency and width of the BP correlated with the water polymorphism of the LLPT scenario, allowing us to distinguish the "low-density liquid" (LDL) and "high-density liquid" (HDL) phases in deeply cooled bulk water.Moreover, the BP properties afford a further confirmation of theWidom line temperatue T[subscript W] as the (P, T) locus in which the local structure of water transforms from a predominately LDL form to a predominately HDL form.
United States. Dept. of Energy (DOE grant DE-FG02-90ER45429)