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Title: Solidification and loss of hydrostaticity in liquid media used for pressure measurements

We carried out a study of the pressure dependence of the solidification temperature in nine pressure transmitting media that are liquid at ambient temperature, under pressures up to 2.3 GPa. These fluids are 1:1 isopentane/n-pentane, 4:6 light mineral oil/n-pentane, 1:1 isoamyl alcohol/n-pentane, 4:1 methanol/ethanol, 1:1 FC72/FC84 (Fluorinert), Daphne 7373, isopentane, and Dow Corning PMX silicone oils 200 and 60,000 cS. We relied on the high sensitivity of the electrical resistivity of Ba(Fe1–xRux)2As2 single crystals to the freezing of the pressure media and cross-checked with corresponding anomalies observed in the resistance of the manganin coil that served as the ambient temperature resistive manometer. In addition to establishing the temperature-pressure line separating the liquid (hydrostatic) and frozen (non-hydrostatic) phases, these data permit rough estimates of the freezing pressure of these media at ambient temperature. As a result, this pressure establishes the extreme limit for the medium to be considered hydrostatic. For higher applied pressures, the medium has to be treated as non-hydrostatic.
ORCiD logo [1] ;  [2] ;  [2] ;  [2] ;  [2]
  1. San Diego State Univ., San Diego, CA (United States)
  2. Ames Lab. and Iowa State Univ., Ames, IA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0034-6748; RSINAK
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 86; Journal Issue: 12; Journal ID: ISSN 0034-6748
American Institute of Physics (AIP)
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
Country of Publication:
United States
47 OTHER INSTRUMENTATION; solidification; high pressure; electrical resistivity; glass transitions; hydrostatics
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1229920