UPt3

Uranium platinum
Names

Other names Platinum--uranium (3/1)
Identifiers
CAS Number	12311-92-1
3D model (JSmol)	Interactive image
PubChem CID	71354824
CompTox Dashboard (EPA)	DTXSID90779273
InChI InChI=1S/3Pt.U Key: YYBWTXHBZRZQRM-UHFFFAOYSA-N
SMILES [Pt].[Pt].[Pt].[U]
Properties
Chemical formula	UPt₃
Molar mass	823.3 g/mol^[1]
Density	19.3 g/cm³
Melting point	1700°C^[2]
Structure
Crystal structure	see text
Space group	P6₃/mmc
Thermochemistry
Std molar entropy (S^⦵₂₉₈)	-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 synthesised in the following ways:^[3]

as an intermetallic compound, by direct fusion of pure components according to stoichiometric calculations:

{\mathsf {3Pt+U\ {\xrightarrow {1700^{o}C}}\ UPt_{3}}}

by reduction of uranium dioxide with hydrogen in the presence of platinum:

{\mathsf {UO_{2}+2H_{2}+3Pt\ {\xrightarrow {1700^{o}C}}\ UPt_{3}+2H_{2}O}}

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

^ ^a ^b PubChem. "Platinum--uranium (3/1)". pubchem.ncbi.nlm.nih.gov. Retrieved 2022-10-18.
^ ^a ^b Lyakishev, N.P., ed. (2001). Диаграммы состояния двойных металлических систем [State diagrams of binary metal systems]. Mechanical Engineering (in Russian). Vol. 3, book 3. Moscow. p. 448. ISBN 5-217-02932-3.{{cite book}}: CS1 maint: location missing publisher (link)
^ ^a ^b ^c Kleykamp, Heiko (1991). "Thermodynamics of the uranium-platinum metals systems" (PDF). Pure and Applied Chemistry. Vol. 63, no. 10. pp. 1401–1408. doi:10.1351/pac199163101401. Archived from the original on 14 February 2015. 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. Vol. 63, no. 5. p. 054522. 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. arXiv:1801.03293. Bibcode:2018PhRvB..97m4512S. doi:10.1103/PhysRevB.97.134512. S2CID 119100443.
^ Predel (1998). "Pt-U (Platinum-Uranium)". 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.
^ Ross, B. A. S.; Peterson, D. E. (1990-06-01). "The Pt-U (Platinum-Uranium) system". Bulletin of Alloy Phase Diagrams. Vol. 11, no. 3. pp. 240–243. doi:10.1007/BF03029291. Retrieved 2022-10-09.
^ Gurtovoy, К. G.; Levitin, R. Z. (October 1987). "Магнетизм актинидов и их соединений" [Magnetism of actinides and their compounds] (PDF). Успехи физических наук (Advances in the Physical Sciences). Vol. 153, no. 2. Retrieved 2022-10-09.
^ Mineev, V. P. (1994). "Superconductivity in UPt3". Annales de Physique. Vol. 19, no. 4. pp. 367–384. doi:10.1051/anphys:01994001904036700. Retrieved 2022-10-09.