Jump to content

Room-temperature superconductor

From Wikipedia, the free encyclopedia

Unsolved problem in physics:
Is it possible to make a material that is a superconductor at room temperature and atmospheric pressure?

A room-temperature superconductor is a hypothetical material capable of displaying superconductivity above 0 °C (273 K; 32 °F), operating temperatures which are commonly encountered in everyday settings. As of 2023, the material with the highest accepted superconducting temperature was highly pressurized lanthanum decahydride, whose transition temperature is approximately 250 K (−23 °C) at 200 GPa.[1][2]

At standard atmospheric pressure, cuprates currently hold the temperature record, manifesting superconductivity at temperatures as high as 138 K (−135 °C).[3] Over time, researchers have consistently encountered superconductivity at temperatures previously considered unexpected or impossible, challenging the notion that achieving superconductivity at room temperature was infeasible.[4][5] The concept of "near-room temperature" transient effects has been a subject of discussion since the early 1950s.

Reports

[edit]

Since the discovery of high-temperature superconductors ("high" being temperatures above 77 K (−196.2 °C; −321.1 °F), the boiling point of liquid nitrogen), several materials have been claimed, although not confirmed, to be room-temperature superconductors.[6]

Corroborated studies

[edit]

In 2014, an article published in Nature suggested that some materials, notably YBCO (yttrium barium copper oxide), could be made to briefly superconduct at room temperature using infrared laser pulses.[7]

In 2015, an article published in Nature by researchers of the Otto Hahn Institute suggested that under certain conditions such as extreme pressure H
2
S
transitioned to a superconductive form H
3
S
at 150 GPa (around 1.5 million times atmospheric pressure) in a diamond anvil cell.[8] The critical temperature is 203 K (−70 °C) which would be the highest Tc ever recorded and their research suggests that other hydrogen compounds could superconduct at up to 260 K (−13 °C).[9][10]

Also in 2018, researchers noted a possible superconducting phase at 260 K (−13 °C) in lanthanum decahydride (LaH
10
) at elevated (200 GPa) pressure.[11] In 2019, the material with the highest accepted superconducting temperature was highly pressurized lanthanum decahydride, whose transition temperature is approximately 250 K (−23 °C).[1][2]

Uncorroborated studies

[edit]

In 1993 and 1997, Michel Laguës and his team published evidence of room temperature superconductivity observed on MBE deposited ultrathin nanostructures of BiSrCaCuO.[12][13] These compounds exhibit extremely low resistivities orders of magnitude below that of copper, strongly non-linear I(V) characteristics and hysteretic I(V) behavior.

In 2000, while extracting electrons from diamond during ion implantation work, Johan Prins claimed to have observed a phenomenon that he explained as room-temperature superconductivity within a phase formed on the surface of oxygen-doped type IIa diamonds in a 10−6 mbar vacuum.[14]

In 2003, a group of researchers published results on high-temperature superconductivity in palladium hydride (PdHx: x > 1)[15] and an explanation in 2004.[16] In 2007, the same group published results suggesting a superconducting transition temperature of 260 K,[17] with transition temperature increasing as the density of hydrogen inside the palladium lattice increases. This has not been corroborated by other groups.

In March 2021, an announcement reported superconductivity in a layered yttrium-palladium-hydron material at 262 K and a pressure of 187 GPa. Palladium may act as a hydrogen migration catalyst in the material.[18]

On 31 December 2023, "Global Room-Temperature Superconductivity in Graphite" was published in the journal Advanced Quantum Technologies, claiming to demonstrate superconductivity at room temperature and ambient pressure in highly oriented pyrolytic graphite with dense arrays of nearly parallel line defects.[19]

Retracted or unreliable studies

[edit]
A magnet is suspended over a liquid nitrogen cooled high-temperature superconductor (−200 °C)
A magnet levitating above a superconductor (at −200 °C) that is exhibiting the Meissner effect.

In 2012, an Advanced Materials article claimed superconducting behavior of graphite powder after treatment with pure water at temperatures as high as 300 K and above.[20][unreliable source?] So far, the authors have not been able to demonstrate the occurrence of a clear Meissner phase and the vanishing of the material's resistance.

In 2018, Dev Kumar Thapa and Anshu Pandey from the Solid State and Structural Chemistry Unit of the Indian Institute of Science, Bangalore claimed the observation of superconductivity at ambient pressure and room temperature in films and pellets of a nanostructured material that is composed of silver particles embedded in a gold matrix.[21] Due to similar noise patterns of supposedly independent plots and the publication's lack of peer review, the results have been called into question.[22] Although the researchers repeated their findings in a later paper in 2019,[23] this claim is yet to be verified and confirmed.[citation needed]

Since 2016, a team led by Ranga P. Dias has produced a number of retracted or challenged papers in this field. In 2016 they claimed observation of solid metallic hydrogen in 2016.[24] In October 2020, they reported room-temperature superconductivity at 288 K (at 15 °C) in a carbonaceous sulfur hydride at 267 GPa, triggered into crystallisation via green laser.[25][26] This was retracted in 2022 after flaws in their statistical methods were identified [27] and led to questioning of other data.[28][29][30][31][32][33] In 2023 he reported superconductivity at 294 K and 1 GPa in nitrogen-doped lutetium hydride, in a paper widely met with skepticism about its methods and data. Later in 2023 he was found to have plagiarized parts of his dissertation from someone else's thesis, and to have fabricated data in a paper on manganese disulfide, which was retracted.[34] The lutetium hydride paper was also retracted.[citation needed] The first attempts to replicate those results failed.[35][36][37]

On July 23, 2023, a Korean team claimed that Cu-doped lead apatite, which they named LK-99, was superconducting up to 370 K, though they had not observed this fully.[38] They posted two preprints to arXiv,[39] published a paper in a journal,[40] and submitted a patent application.[41] The reported observations were received with skepticism by experts due to the lack of clear signatures of superconductivity.[42] The story was widely discussed on social media, leading to a large number of attempted replications, none of which had more than qualified success. By mid-August, a series of papers from major labs provided significant evidence that LK-99 was not a superconductor, finding resistivity much higher than copper, and explaining observed effects such as magnetic response and resistance drops in terms of impurities and ferromagnetism in the material.[43][44]

Theories

[edit]

Metallic hydrogen and phonon-mediated pairing

[edit]

Theoretical work by British physicist Neil Ashcroft predicted that solid metallic hydrogen at extremely high pressure (~500 GPa) should become superconducting at approximately room temperature, due to its extremely high speed of sound and expected strong coupling between the conduction electrons and the lattice-vibration phonons.[45]

A team at Harvard University has claimed to make metallic hydrogen and reports a pressure of 495 GPa.[46] Though the exact critical temperature has not yet been determined, weak signs of a possible Meissner effect and changes in magnetic susceptibility at 250 K may have appeared in early magnetometer tests on an original now-lost sample. A French team is working with doughnut shapes rather than planar at the diamond culette tips.[47]

Organic polymers and exciton-mediated pairing

[edit]

In 1964, William A. Little proposed the possibility of high-temperature superconductivity in organic polymers.[48]

Other hydrides

[edit]

In 2004, Ashcroft returned to his idea and suggested that hydrogen-rich compounds can become metallic and superconducting at lower pressures than hydrogen. More specifically, he proposed a novel way to pre-compress hydrogen chemically by examining IVa hydrides.[49]

In 2014–2015, conventional superconductivity was observed in a sulfur hydride system (H
2
S
or H
3
S
) at 190 K to 203 K at pressures of up to 200 GPa.

In 2016, research suggested a link between palladium hydride containing small impurities of sulfur nanoparticles as a plausible explanation for the anomalous transient resistance drops seen during some experiments, and hydrogen absorption by cuprates was suggested in light of the 2015 results in H
2
S
as a plausible explanation for transient resistance drops or "USO" noticed in the 1990s by Chu et al. during research after the discovery of YBCO.[50]

It has been predicted that ScH
12
(scandium dodecahydride) would exhibit superconductivity at room temperature – Tc between 333 K (60 °C) and 398 K (125 °C) – under a pressure expected not to exceed 100 GPa.[51]

Some research efforts are currently moving towards ternary superhydrides, where it has been predicted that Li
2
MgH
16
(dilithium magnesium hexadecahydride) would have a Tc of 473 K (200 °C) at 250 GPa.[52][53]

Spin coupling

[edit]

It is also possible that if the bipolaron explanation is correct, a normally semiconducting material can transition under some conditions into a superconductor if a critical level of alternating spin coupling in a single plane within the lattice is exceeded; this may have been documented in very early experiments from 1986. The best analogy here would be anisotropic magnetoresistance, but in this case the outcome is a drop to zero rather than a decrease within a very narrow temperature range for the compounds tested similar to "re-entrant superconductivity".[54]

In 2018, support was found for electrons having anomalous 3/2 spin states in YPtBi.[55] Though YPtBi is a relatively low temperature superconductor, this does suggest another approach to creating superconductors.[56]

"Quantum bipolarons" could describe how a material might superconduct at up to nearly room temperature.[57]

References

[edit]
  1. ^ a b Somayazulu, Maddury; Ahart, Muhtar; Mishra, Ajay Kumar; Geballe, Zachary M.; Baldini, Maria; Meng, Yue; Struzhkin, Viktor V.; Hemley, Russell Julian (2019). "Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures". Phys. Rev. Lett. 122 (2): 027001. arXiv:1808.07695. Bibcode:2019PhRvL.122b7001S. doi:10.1103/PhysRevLett.122.027001. PMID 30720326. S2CID 53622077.
  2. ^ a b Drozdov, Alexander P.; Kong, Panpan; Minkov, Vasily S.; Besedin, Stanislav P.; Kuzovnikov, Mikhail A.; Mozaffari, Shirin; Balicas, Luis; Balakirev, Fedor F.; Graf, David E.; Prakapenka, Vitali B.; Greenberg, Eran; Knyazev, Dmitry A.; Tkacz, Marek; Eremets, Mikhail Ivanovich (2019). "Superconductivity at 250 K in lanthanum hydride under high pressures". Nature. 569 (7757): 528–531. arXiv:1812.01561. Bibcode:2019Natur.569..528D. doi:10.1038/s41586-019-1201-8. PMID 31118520. S2CID 119231000.
  3. ^ Dai, Pengcheng; Chakoumakos, Bryan C.; Sun, G.F.; Wong, Kai Wai; Xin, Ying; Lu, D.F. (1995). "Synthesis and neutron powder diffraction study of the superconductor HgBa2Ca2Cu3O8+δ by Tl substitution". Physica C. 243 (3–4): 201–206. Bibcode:1995PhyC..243..201D. doi:10.1016/0921-4534(94)02461-8.
  4. ^ Geballe, Theodore Henry (12 March 1993). "Paths to Higher Temperature Superconductors". Science. 259 (5101): 1550–1551. Bibcode:1993Sci...259.1550G. doi:10.1126/science.259.5101.1550. PMID 17733017.
  5. ^ Jones, Barbara A.; Roche, Kevin P. (25 July 2016). "Almaden Institute 2012: Superconductivity 297 K – Synthetic Routes to Room Temperature Superconductivity". researcher.watson.ibm.com. Archived from the original on 12 December 2013. Retrieved 18 September 2018.
  6. ^ Garisto, Dan (27 July 2023). "Viral New Superconductivity Claims Leave Many Scientists Skeptical". Scientific American. Archived from the original on 27 July 2023. Retrieved 28 July 2023.
  7. ^ Mankowsky, Roman; Subedi, Alaska; Först, Michael; Mariager, Simon O.; Chollet, Matthieu; Lemke, Henrik T.; Robinson, Joseph Stephen; Glownia, James M.; Minitti, Michael P.; Frano, Alex; Fechner, Michael; Spaldin, Nicola Ann; Loew, Toshinao; Keimer, Bernhard; Georges, Antoine; Cavalleri, Andrea (2014). "Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5". Nature. 516 (7529): 71–73. arXiv:1405.2266. Bibcode:2014Natur.516...71M. doi:10.1038/nature13875. PMID 25471882. S2CID 3127527.
  8. ^ Drozdov, A. P.; Eremets, M. I.; Troyan, I. A.; Ksenofontov, V.; Shylin, S. I. (2015). "Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system". Nature. 525 (7567): 73–76. arXiv:1506.08190. Bibcode:2015Natur.525...73D. doi:10.1038/nature14964. ISSN 0028-0836. PMID 26280333. S2CID 4468914. Archived from the original on 6 May 2021. Retrieved 9 June 2021.
  9. ^ Cartlidge, Edwin (18 August 2015). "Superconductivity record sparks wave of follow-up physics". Nature. 524 (7565): 277. Bibcode:2015Natur.524..277C. doi:10.1038/nature.2015.18191. PMID 26289188.
  10. ^ Ge, Yanfeng; Zhang, Fan; Yao, Yugui (2016). "First-principles demonstration of superconductivity at 280 K (7 °C) in hydrogen sulfide with low phosphorus substitution". Phys. Rev. B. 93 (22): 224513. arXiv:1507.08525. Bibcode:2016PhRvB..93v4513G. doi:10.1103/PhysRevB.93.224513. S2CID 118730557. Archived from the original on 7 November 2017. Retrieved 6 November 2017.
  11. ^ Grant, Andrew (23 August 2018). "Pressurized superconductors approach room-temperature realm". Physics Today (8): 30438. Bibcode:2018PhT..2018h0438G. doi:10.1063/PT.6.1.20180823b. S2CID 240297717.
  12. ^ Laguës et al. "Evidence suggesting superconductivity at 250 K in a sequentially deposited cuprate film" Science 262, 1850 (1993)
  13. ^ Laguës et al. "Room temperature transport properties of new BiSrCaCuO compounds" C.R.Acad.Sci. Paris, 324, 627 (1997)
  14. ^ Prins, Johan F. (1 March 2003). "The diamond vacuum interface: II. Electron extraction from n-type diamond: evidence for superconduction at room temperature". Semiconductor Science and Technology. 18 (3): S131 – S140. Bibcode:2003SeScT..18S.131P. doi:10.1088/0268-1242/18/3/319. S2CID 250881569.
  15. ^ Tripodi, Paolo; Di Gioacchino, Daniele; Borelli, Rodolfo; Vinko, Jenny Darja (May 2003). "Possibility of high temperature superconducting phases in PdH". Physica C. 388–389: 571–572. Bibcode:2003PhyC..388..571T. doi:10.1016/S0921-4534(02)02745-4.
  16. ^ Tripodi, Paolo; Di Gioacchino, Daniele; Vinko, Jenny Darja (August 2004). "Superconductivity in PdH: Phenomenological explanation". Physica C. 408–410: 350–352. Bibcode:2004PhyC..408..350T. doi:10.1016/j.physc.2004.02.099.
  17. ^ Tripodi, Paolo; Di Gioacchino, Daniele; Vinko, Jenny Darja (2007). "A review of high temperature superconducting property of PdH system". International Journal of Modern Physics B. 21 (18&19): 3343–3347. Bibcode:2007IJMPB..21.3343T. doi:10.1142/S0217979207044524.
  18. ^ "A material that is superconductive at room temperature and lower pressure". Archived from the original on 22 March 2021. Retrieved 22 March 2021.
  19. ^ Kopelevich, Yakov; Torres, José; Da Silva, Robson; Oliveira, Felipe; Diamantini, Maria Cristina; Trugenberger, Carlo; Vinokur, Valerii (2023). "Global Room-Temperature Superconductivity in Graphite". Advanced Quantum Technologies. 7 (2). arXiv:2208.00854. doi:10.1002/qute.202300230.
  20. ^ Scheike, Thomas; Böhlmann, Winfried; Esquinazi, Pablo; Barzola-Quiquia, José; Ballestar, Ana; Setzer, Annette (2012). "Can Doping Graphite Trigger Room Temperature Superconductivity? Evidence for Granular High-Temperature Superconductivity in Water-Treated Graphite Powder". Advanced Materials. 24 (43): 5826–5831. arXiv:1209.1938. Bibcode:2012AdM....24.5826S. doi:10.1002/adma.201202219. PMID 22949348. S2CID 205246535.
  21. ^ Thapa, Dev Kumar; Pandey, Anshu (2018). "Evidence for superconductivity at ambient temperature and pressure in nanostructures". arXiv:1807.08572 [cond-mat.supr-con].
  22. ^ Desikan, Shubashree (18 August 2018). "IISc duo's claim of ambient superconductivity may have support in theory". The Hindu. Archived from the original on 24 June 2020. Retrieved 4 October 2018.
  23. ^ Prasad, R.; Desikan, Shubashree (25 May 2019). "Finally, IISc team confirms breakthrough in superconductivity at room temperature". The Hindu. Archived from the original on 26 May 2019. Retrieved 26 May 2019 – via www.thehindu.com.
  24. ^ Garisto, Dan (9 March 2023). "Allegations of Scientific Misconduct Mount as Physicist Makes His Biggest Claim Yet". Physics. 16: 40. Bibcode:2023PhyOJ..16...40G. doi:10.1103/Physics.16.40. S2CID 257615348. Archived from the original on 21 March 2023. Retrieved 21 March 2023.
  25. ^ Chang, Kenneth (14 October 2020). "Finally, the First Room-Temperature Superconductor". The New York Times. Archived from the original on 14 October 2020. Retrieved 14 October 2020.
  26. ^ Snider, Elliot; Dasenbrock-Gammon, Nathan; McBride, Raymond; Debessai, Mathew; Vindana, Hiranya; Vencatasamy, Kevin; Lawler, Keith V.; Salamat, Ashkan; Dias, Ranga P. (October 2020). "Room-temperature superconductivity in a carbonaceous sulfur hydride". Nature. 586 (7829): 373–377. Bibcode:2020Natur.586..373S. doi:10.1038/s41586-020-2801-z. OSTI 1673473. PMID 33057222. S2CID 222823227. (Retracted, see doi:10.1038/s41586-022-05294-9, PMID 36163290)
  27. ^ van der Marel, Dirk; Hirsch, Jorge E. (19 January 2022). "Comment on Nature 586, 373 (2020) by E. Snider et al". International Journal of Modern Physics B. 37 (4): 2375001. arXiv:2201.07686. doi:10.1142/S0217979223750012. ISSN 0217-9792. S2CID 252324362.
  28. ^ Hand, Eric (26 September 2022). "'Something is Seriously Wrong':Room-Temperature superconductivity study retracted". Science. Archived from the original on 27 September 2022. Retrieved 27 September 2022.
  29. ^ Dasenbrock-Gammon, Nathan; Snider, Elliot; McBride, Raymond; Pasan, Hiranya; Durkee, Dylan; Khalvashi-Sutter, Nugzari; Munasinghe, Sasanka; Dissanayake, Sachith E.; Lawler, Keith V.; Salamat, Ashkan; Dias, Ranga P. (9 March 2023). "Evidence of near-ambient superconductivity in a N-doped lutetium hydride". Nature. 615 (7951): 244–250. Bibcode:2023Natur.615..244D. doi:10.1038/s41586-023-05742-0. PMID 36890373. S2CID 257407449. Archived from the original on 8 March 2023. Retrieved 8 March 2023 – via www.nature.com. (Retracted, see doi:10.1038/s41586-023-06774-2, PMID 37935926)
  30. ^ Woodward, Aylin (8 March 2023). "The Scientific Breakthrough That Could Make Batteries Last Longer". Wall Street Journal. Archived from the original on 8 March 2023. Retrieved 8 March 2023.
  31. ^ "'Revolutionary' blue crystal resurrects hope of room temperature superconductivity". www.science.org. Archived from the original on 8 March 2023. Retrieved 8 March 2023.
  32. ^ Anderson, Margo (8 March 2023). "Room-Temperature Superconductivity Claimed". IEEE Spectrum. Institute of Electrical and Electronics Engineers. Archived from the original on 9 March 2023. Retrieved 9 March 2023.
  33. ^ Wood, Charlie; Savitsky, Zack (8 March 2023). "Room-Temperature Superconductor Discovery Meets With Resistance". Quanta Magazine. Simons Foundation. Archived from the original on 14 March 2023. Retrieved 14 March 2023.
  34. ^ Garisto, Dan (9 March 2023). "Allegations of Scientific Misconduct Mount as Physicist Makes His Biggest Claim Yet". Physics. 16: 40. Bibcode:2023PhyOJ..16...40G. doi:10.1103/Physics.16.40. S2CID 257615348.
  35. ^ Yirka, Bob (17 May 2023). "Replication of room-temperature superconductor claims fails to show superconductivity". Archived from the original on 18 June 2023. Retrieved 18 June 2023.
  36. ^ Wilkins, Alex (17 March 2023). "'Red matter' superconductor may not be a wonder material after all". New Scientist. Archived from the original on 21 March 2023.
  37. ^ Salke, Nilesh P.; Mark, Alexander C.; Ahart, Muhtar; Hemley, Russell J. (9 June 2023). "Evidence for Near Ambient Superconductivity in the Lu-N-H System". arXiv:2306.06301 [cond-mat].
  38. ^ Lee, Sukbae; Kim, Ji-Hoon; Kwon, Young-Wan (2023). "The First Room-Temperature Ambient-Pressure Superconductor". arXiv:2307.12008 [cond-mat.supr-con].
  39. ^ Lee, Sukbae; Kim, Jihoon; Kim, Hyun-Tak; Im, Sungyeon; An, SooMin; Keun Ho Auh (2023). "Superconductor Pb10−xCux(PO4)6O showing levitation at room temperature and atmospheric pressure and mechanism". arXiv:2307.12037 [cond-mat.supr-con].
  40. ^ Lee, Sukbae; Kim, Jihoon; Im, Sungyeon; An, Soomin; Kwon, Young-Wan; Ho, Auh Keun (April 2023). "다음논문 Consideration for the development of room-temperature ambient-pressure superconductor (LK-99)". Journal of the Korean Crystal Growth and Crystal Technology. 33 (2): 61–70. Archived from the original on 26 July 2023. Retrieved 26 July 2023.
  41. ^ "Room temperature and normal pressure superconducting ceramic compound, and method for manufacturing same". Archived from the original on 26 July 2023. Retrieved 26 July 2023.
  42. ^ Padavic-Callaghn, Karmela (26 July 2023). "Room-temperature superconductor 'breakthrough' met with scepticism". New Scientist. Retrieved 26 July 2023.
  43. ^ Johnson, Carolyn (9 August 2023). "A superconductor claim blew up online. Science has punctured it". The Washington Post. Retrieved 9 August 2023.
  44. ^ Orf, Darren (9 August 2023). "Well, Seems Like LK-99 Isn't a Room Temperature Superconductor After All". Popular Mechanics. Retrieved 9 August 2023.
  45. ^ Ashcroft, N. W. (1968). "Metallic Hydrogen: A High-Temperature Superconductor?". Physical Review Letters. 21 (26): 1748–1749. Bibcode:1968PhRvL..21.1748A. doi:10.1103/PhysRevLett.21.1748.
  46. ^ Johnston, Ian (26 January 2017). "Hydrogen turned into metal in stunning act of alchemy that could revolutionise technology and spaceflight". The Independent. Archived from the original on 3 May 2019. Retrieved 12 December 2017.
  47. ^ Loubeyre, Paul; Occelli, Florent; Dumas, Paul (2019). "Observation of a first order phase transition to metal hydrogen near 425 GPa". arXiv:1906.05634 [cond-mat.mtrl-sci].
  48. ^ Little, W. A. (1964). "Possibility of Synthesizing an Organic Superconductor". Physical Review. 134 (6A): A1416 – A1424. Bibcode:1964PhRv..134.1416L. doi:10.1103/PhysRev.134.A1416.
  49. ^ Ashcroft, N. W. (2004). "Hydrogen Dominant Metallic Alloys: High Temperature superconductors". Physical Review Letters. 92 (18): 1748–1749. Bibcode:2004PhRvL..92r7002A. doi:10.1103/PhysRevLett.92.187002. PMID 15169525.
  50. ^ Transient High-Temperature Superconductivity in Palladium Hydride. Griffith University (Griffith thesis). Griffith University. 2016. Archived from the original on 6 August 2020. Retrieved 2 December 2019.
  51. ^ Jiang, Qiwen; Duan, Defang; Song, Hao; Zhang, Zihan; Huo, Zihao; Cui, Tian; Yao, Yansun (2024). "Prediction of Room-Temperature Superconductivity in Quasi-Atomic H2-Type Hydrides at High Pressure". Advanced Science. 11 (35): e2405561. arXiv:2302.02621. doi:10.1002/advs.202405561. PMC 11425200. PMID 39033541.
  52. ^ Sun, Ying; Lv, Jian; Xie, Yu; Liu, Hanyu; Ma, Yanming (26 August 2019). "Route to a Superconducting Phase above Room Temperature in Electron-Doped Hydride Compounds under High Pressure". Physical Review Letters. 123 (9): 097001. Bibcode:2019PhRvL.123i7001S. doi:10.1103/PhysRevLett.123.097001. PMID 31524448. S2CID 202123043. Archived from the original on 26 November 2020. Retrieved 9 January 2022. The recent theory-orientated discovery of record high-temperature superconductivity (Tc~250 K) in sodalitelike clathrate LaH10 is an important advance toward room-temperature superconductors. Here, we identify an alternative clathrate structure in ternary Li
    2
    MgH
    16
    with a remarkably high estimated Tc of ~473 K at 250 GPa, which may allow us to obtain room-temperature or even higher-temperature superconductivity.
  53. ^ Extance, Andy (1 November 2019). "The race is on to make the first room temperature superconductor". www.chemistryworld.com. Royal Society of Chemistry. Archived from the original on 30 December 2019. Retrieved 30 December 2019. In August, Ma and colleagues published a study that showed the promise of ternary superhydrides. They predicted that Li
    2
    MgH
    16
    would have a Tc of 473 K at 250 GPa, far in excess of room temperature.
  54. ^ Di Grezia, E.; Esposito, S.; Salesi, G. (2007). "Superconductors with two critical temperatures". Physica C. 451 (2): 86. arXiv:cond-mat/0607303. Bibcode:2007PhyC..451...86D. doi:10.1016/j.physc.2006.10.013.
  55. ^ MacDonald, Fiona (9 April 2018). "Physicists Just Discovered an Entirely New Type of Superconductivity". ScienceAlert. Archived from the original on 7 February 2019. Retrieved 6 February 2019.
  56. ^ Kim, Hyunsoo; Wang, Kefeng; Nakajima, Yasuyuki; Hu, Rongwei; Ziemak, Steven; Syers, Paul; Wang, Limin; Hodovanets, Halyna; Denlinger, Jonathan D.; Brydon, Philip M. R.; Agterberg, Daniel F.; Tanatar, Makariy A.; Prozorov, Ruslan; Paglione, Johnpierre (2018). "Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal". Science Advances. 4 (4): eaao4513. arXiv:1603.03375. Bibcode:2018SciA....4.4513K. doi:10.1126/sciadv.aao4513. PMC 5938259. PMID 29740606.
  57. ^ "High-temperature superconductivity: Exploring quadratic electron-phonon coupling".