Extended and accurate determination of the melting curves of argon, helium, ice(H2O),and hydrogen(H2)
| Autor: | P. Loubeyre, René LeToullec, Frédéric Datchi |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Physics
Maximum temperature Argon Hydrogen Analytical chemistry chemistry.chemical_element 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Diamond anvil cell Ice VII Nuclear magnetic resonance Helium-4 chemistry 0103 physical sciences 010306 general physics 0210 nano-technology Helium |
| Zdroj: | Physical Review B. 61:6535-6546 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.61.6535 |
| Popis: | The melting curves of argon, helium 4, ice $({\mathrm{H}}_{2}\mathrm{O}),$ and hydrogen $({\mathrm{H}}_{2})$ have been measured from room temperature up to a maximum temperature of 750 K. This extends the previous determination of the melting lines of ${\mathrm{H}}_{2}$ and He by nearly a factor of 2 in pressure. The experiments were carried out with a resistively heated diamond anvil cell. Improved accuracy with respect to previous determinations, when existing, was achieved by the use of an optical metrology which gives an in situ measurement of both the pressure and temperature of the sample. The melting lines of argon and ${\mathrm{H}}_{2}\mathrm{O}$ are found to be well represented by the following Simon-Glatzel equations: $P=2.172\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}{T}^{1.556}\ensuremath{-}0.21$ (argon) and $P=2.17+1.253[{(T/354.8)}^{3.0}\ensuremath{-}1]$ $({\mathrm{H}}_{2}\mathrm{O}).$ But the Simon-Glatzel form was found inadequate to reproduce the melting data of ${}^{4}\mathrm{He}$ and ${\mathrm{H}}_{2}$ over the whole temperature range. In the case of ${}^{4}\mathrm{He},$ this deviation from a Simon law is explained by the softening of the pair interaction with density. A Kechin equation is proposed for ${\mathrm{H}}_{2}:$ ${T=14.025(1+P/0.0286)}^{0.589}\mathrm{exp}(\ensuremath{-}4.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}P).$ This form is in excellent agreement with all published experimental data for ${\mathrm{H}}_{2}$ and interestingly predicts a maximum on the melting curve at 128 GPa and 1100 K. |
| Databáze: | OpenAIRE |
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