Liquid–solid phase transition of hydrogen and deuterium in silica aerogel

Journal Article · Tue Oct 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4900540· OSTI ID:22308149

Van Cleve, E.; Worsley, M. A.

Behavior of hydrogen isotopes confined in disordered low-density nanoporous solids remains essentially unknown. Here, we use relaxation calorimetry to study freezing and melting of H{sub 2} and D{sub 2} in an ∼85%-porous base-catalyzed silica aerogel. We find that liquid–solid transition temperatures of both isotopes inside the aerogel are depressed. The phase transition takes place over a wide temperature range of ∼4 K and non-trivially depends on the liquid filling fraction, reflecting the broad pore size distribution in the aerogel. Undercooling is observed for both H{sub 2} and D{sub 2} confined inside the aerogel monolith. Results for H{sub 2} and D{sub 2} are extrapolated to tritium-containing hydrogens with the quantum law of corresponding states.

• OSTI ID: 22308149
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALORIMETRY
DENSITY
DEUTERIUM
DISTRIBUTION
FREEZING
HYDROGEN
LIQUIDS
MELTING
PHASE TRANSFORMATIONS
POROUS MATERIALS
RELAXATION
SILICA
SOLIDS
SUBCOOLING
TRANSITION TEMPERATURE
TRITIUM