phase diagram for carbon dioxide phase diagram for carbon dioxide - - PDF document

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phase diagram for carbon dioxide

triple point: solid, liquid and gas

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phase diagram for carbon dioxide

source: NIST fluid data

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Phase Diagram of CO2 to High Pressure

x-ray diffraction through diamond anvil

source: Choong-Shik Yoo, PCCP, 2013, 15, 7949.

polymeric ?

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Phases I, II, and III of CO2

source: Yanqiang Han, et al., npj Quantum Materials, 2019, 4:10, 1-7.

structures from quantum- mechanical perturbation theory (MP2)

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Phases I, II, and III of CO2

source: Yanqiang Han, et al., npj Quantum Materials, 2019, 4:10, 1-7.

II and III I and III P(GPa) T(K) P(GPa) T(K) 12 524 13.8 98 13 531 13.4 198 14 543 12.6 298 15 554 11.6 398

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Phases I, II, and III of CO2

source: Yanqiang Han, et al., npj Quantum Materials, 2019, 4:10, 1-7. Han's new points are in red and blue. Main conclusion: There is a phase II-III boundary.

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3He and 4He phase diagrams

source: Aalto University School of Science, Finland http://ltl.tkk.fi/research/theory/helium.html

helium-4 nuclear spin = 0

abundance 99.9998%

helium-3 nuclear spin = ½

1 MPa = 10 bar

I II

λ line standard boiling point solid has higher entropy

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diamond-anvil cell

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metallic hydrogen observed?

source: Robert Service, "Metallic hydrogen created in diamond vise," Science, 355(6323), 332-333, 27 January 2017. Experiments by Isaac Silvera and Ranga Dias at Harvard. Hydrogen became "shiny and reddish." Metallic character identified by Raman scattering. As of 2018 Silvera and Dias stand by their conclusions. Neil Ashcroft: "very convincing" Eugene Gregoryanz, "the word garbage cannot really describe it."

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metallic hydrogen observed?

T = 5K

source: Ranga Dias and Isaac Silvera, "Observation of the Wigner-Huntington transition to metallic hydrogen," Science, 355(6326), 715-718, 2017.