Comment on “Boson Peak in Deeply Cooled Confined Water: A Possible Way to Explore the Existence of the Liquid-to-Liquid Transition in Water”
- Consiglio Nazionale delle Ricerche Istituto Officina dei Materiali, Operative Group in Grenoble (OGG) c/o Institut Laue Langevin (France)
- Centre for Life Nano Science IIT at Sapienza Istituto Italiano di Tecnologia, Roma (Italy)
In their Letter, Wang et al. report on an inelastic neutron scattering (INS) experiment where they describe the pressure evolution of a low energy (E ~ 6 meV) excitation, emerging in confined protonated water only below 230 K at an exchanged momentum Q=2.0 Å-1. Also, water confinement was used to overcome the unavoidable crystallization occurring below ~250 K in bulk water. The authors report that a similar finding was also obtained in both bulk (numerical simulations) and confined water at ambient pressure. They refer to this low temperature excitation as a boson peak (BP), and relate its occurrence to the Widom line, concluding that the observed pressure behavior of the BP reveals the signature of the high-density liquid (HDL) to the low-density liquid (LDL) transition proposed, though severely questioned, for bulk water. Lastly, we believe these claims to be unconvincing for the following reasons.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1356955
- Journal Information:
- Physical Review Letters, Vol. 115, Issue 14; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Search for the First-Order Liquid-to-Liquid Phase Transition in Low-Temperature Confined Water by Neutron Scattering
Dynamic crossover in deeply cooled water confined in MCM-41 at 4 kbar and its relation to the liquid-liquid transition hypothesis