Chemistry:UPt3
From HandWiki
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| Names | |
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| Other names
Platinum--uranium (3/1)
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| UPt3 | |
| Molar mass | 823.3 g/mol[1] |
| Density | 19.3 g/cm3 |
| Melting point | 1700°C[2] |
| Structure | |
| see text | |
| P63/mmc | |
| Thermochemistry | |
Std molar
entropy (S |
-111 J·mol−1·K−1[3] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
UPt3 is an inorganic binary intermetallic crystalline compound of platinum and uranium.[1]
Production
It can be syntetized in the following ways:[3]
- as an intermetallic compound, by direct fusion of pure components according to stoichiometric calculations:
- [math]\displaystyle{ \mathsf{ 3 Pt + U \ \xrightarrow{1700^oC}\ UPt_3 } }[/math]
- by reduction of uranium dioxide with hydrogen in the presence of platinum:
- [math]\displaystyle{ \mathsf{ UO_2 + 2 H_2 + 3 Pt \ \xrightarrow{1700^oC}\ UPt_3 + 2 H_2O } }[/math]
Physical properties
UPt3 forms crystals of hexagonal symmetry (some studies hypothesize a trigonal structure instead[4]), space group P63/mmc,[5] cell parameters a = 0.5766 nm and c = 0.4898 nm (c should be understood as distance from planes), with a structure similar to nisnite (Ni3Sn) and MgCd3.[6][7]
The compound congruently melts at 1700 °C.[2] The enthalpy of formation of the compound is -111 kJ/mol.[3]
At temperatures below 1 K it becomes superconducting, thought to be due to the presence of heavy fermions (the uranium atoms).[8][9]
References
- ↑ 1.0 1.1 PubChem. "Platinum--uranium (3/1)" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/71354824.
- ↑ 2.0 2.1 Lyakishev, N.P., ed (2001) (in russian). Диаграммы состояния двойных металлических систем. Mechanical Engineering. 3, book 3. Moscow. p. 448. ISBN 5-217-02932-3.
- ↑ 3.0 3.1 3.2 Kleykamp, Heiko (1991). "Thermodynamics of the uranium-platinum metals systems" (in en). Pure and Applied Chemistry 63 (10): 1401–1408. doi:10.1351/pac199163101401. http://publications.iupac.org/pac/63/10/1401/index.html. Retrieved 2022-10-17.
- ↑ Walko, D. A.; Hong, J.-I.; Chandrasekhar Rao, T. V. (2001-01-16). "Crystal structure assignment for the heavy-fermion superconductor UPt3". Physical Review B 63 (5): 054522. doi:10.1103/PhysRevB.63.054522. https://link.aps.org/doi/10.1103/PhysRevB.63.054522. Retrieved 2022-10-18.
- ↑ Sumita, Shuntaro; Yanase, Youichi (2018-04-13). "Unconventional superconducting gap structure protected by space group symmetry". Physical Review B 97 (13): 134512. doi:10.1103/PhysRevB.97.134512. Bibcode: 2018PhRvB..97m4512S.
- ↑ Predel (1998). "Pt-U (Platinum-Uranium)" (in en). Ni-Np – Pt-Zr. Landolt-Börnstein - Group IV Physical Chemistry. Springer-Verlag. pp. 1–2. doi:10.1007/10542753_2536. ISBN 3-540-61712-4. https://dx.doi.org/10.1007/10542753_2536.
- ↑ Ross, B. A. S.; Peterson, D. E. (1990-06-01). "The Pt-U (Platinum-Uranium) system" (in en). Bulletin of Alloy Phase Diagrams 11 (3): 240–243. doi:10.1007/BF03029291. https://doi.org/10.1007/BF03029291. Retrieved 2022-10-09.
- ↑ Gurtovoy, К. G.; Levitin, R. Z. (October 1987). "Магнетизм актинидов и их соединений". Успехи физических наук (Advances in the Physical Sciences) 153 (2). https://ufn.ru/ufn87/ufn87_10/Russian/r8710b.pdf. Retrieved 2022-10-09.
- ↑ Mineev, V. P. (1994). "Superconductivity in UPt3" (in en). Annales de Physique 19 (4): 367–384. doi:10.1051/anphys:01994001904036700. https://www.annphys.org/articles/anphys/abs/1994/04/anphys_1994__19_4_367_0/anphys_1994__19_4_367_0.html. Retrieved 2022-10-09.
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