Time-Resolved Study of Crystallization in Deeply Cooled Liquid Parahydrogen
Abstract
We present real-time measurements of the crystallization process occurring in liquid para-hydrogen (para-H2) quenched to ≈0.65Tm (Tm=13.8K is the melting point of bulk liquid para-H2). The combination of high spatial resolution Raman spectroscopy and liquid microjet generation allows, in situ, capturing structural changes with ∼10-8s time resolution. Our results provide a crystal growth rate that rules out a thermally activated freezing process and reveal that the quenched melt freezes into a metastable polymorph, which undergoes a structural transition. The achieved temporal control offers new opportunities for exploring the elementary processes of nonequilibrium phase transformations in supercooled liquids.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 2011
- DOI:
- 10.1103/PhysRevLett.106.245301
- Bibcode:
- 2011PhRvL.106x5301K
- Keywords:
-
- 67.63.Cd;
- 33.20.Fb;
- 64.60.My;
- 64.70.dg;
- Molecular hydrogen and isotopes;
- Raman and Rayleigh spectra;
- Metastable phases;
- Crystallization of specific substances