Experimental Evidence for a Liquid-Liquid Crossover in Deeply Cooled Confined Water - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Review Letters Année : 2014

Experimental Evidence for a Liquid-Liquid Crossover in Deeply Cooled Confined Water

Résumé

In this work we investigate, by means of elastic neutron scattering, the pressure dependence of mean square displacements (MSD) of hydrogen atoms of deeply cooled water confined in the pores of a three-dimensional disordered SiO 2 xerogel; experiments have been performed at 250 and 210 K from atmospheric pressure to 1200 bar. The " pressure anomaly " of supercooled water (i.e., a mean square displacement increase with increasing pressure) is observed in our sample at both temperatures; however, contrary to previous simulation results and to the experimental trend observed in bulk water, the pressure effect is smaller at lower (210 K) than at higher (250 K) temperature. Elastic neutron scattering results are complemented by differential scanning calorimetry data that put in evidence, besides the glass transition at about 170 K, a first-order-like endothermic transition occurring at about 230 K that, in view of the neutron scattering results, can be attributed to a liquid-liquid crossover. Our results give experimental evidence for the presence, in deeply cooled confined water, of a crossover occurring at about 230 K (at ambient pressure) from a liquid phase predominant at 210 K to another liquid phase predominant at 250 K; therefore, they are fully consistent with the liquid-liquid transition hypothesis.
Fichier principal
Vignette du fichier
PhysRevLett.113.215701.pdf (350.45 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01582604 , version 1 (06-09-2017)

Identifiants

Citer

Antonio Cupane, Margarita Fomina, Irina Piazza, Judith Peters, Giorgio Schirò. Experimental Evidence for a Liquid-Liquid Crossover in Deeply Cooled Confined Water. Physical Review Letters, 2014, 113 (21), pp.215701. ⟨10.1103/PhysRevLett.113.215701⟩. ⟨hal-01582604⟩
242 Consultations
141 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More