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'A '''room-temperature superconductor''' is a hypothetical material which would be capable of exhibiting [[superconductivity]] at [[operating temperature]]s above 0°&nbsp;[[celsius|C]] (273.15&nbsp;[[Kelvin|K]]). While this is not strictly "room temperature" (which would be approx. 20–25&nbsp;°C), it is the temperature at which ice forms and can be reached and maintained easily in an everyday environment. At present, the highest temperature superconducting materials are the [[High-temperature superconductor#Cuprates|cuprates]], which have demonstrated superconductivity at atmospheric pressure at temperatures as high as -135 °C (138 K).<ref>{{cite journal | author = P. Dai, B.C. Chakoumakos, G.F. Sun, K.W. Wong, Y. Xin, D.F. Lu | title = Synthesis and neutron powder diffraction study of the superconductor HgBa2Ca2Cu3O8 + δ by Tl substitution | journal = Physica C | volume = 243 | issue = 3-4 | pages = 201-206 | year = 1995 | doi = 10.1016/0921-4534(94)02461-8|bibcode = 1995PhyC..243..201D }}</ref> It is unknown whether any material exhibiting room-temperature superconductivity exists. The interest in its discovery arises from the repeated discovery of superconductivity at temperatures previously unexpected or held to be impossible. The potential benefits for society and science if such a material did exist are profound. ==Reports== Since the discovery of [[high-temperature superconductor]]s, several materials have been reported to be room-temperature superconductors, although none of these reports has been confirmed. <!--rewrote to what cites now have: EE Times admitted "A March 17 story about new research on the potential superconducting properties of the material silane contained numerous errors.". Note that there is no mention of "potential" or "room temperature" nor of how to "reduce the pressure requirements" of metallic hydrogen. This part would go better in the Silane article, as there is no connection with room-temperature here any longer. Could associating the team with these erroneously reported claims be deemed slanderous? --> In 2008, an [[EE Times]] article claimed that room-temperature superconductivity had been achieved in [[silane]] compressed to a solid at high pressure.<ref>{{Cite document |title=EE Times corrects story on silane as a potential superconductor |url=http://www.eetimes.com/electronics-news/4076616/EE-Times-corrects-story-on-silane-as-a-potential-superconductor |publisher=[[EE Times]]|date=24 March 2008 |accessdate=2012-06-27 |postscript=<!--None-->}}</ref> However, the work described in the article only found a transition temperature of 17 K at 96 and 120 GPa,<ref>{{cite journal | author = M. I. Eremets, I. A. Trojan, S. A. Medvedev, J. S. Tse, Y. Yao | title = Superconductivity in Hydrogen Dominant Materials: Silane | journal = Science | volume = 319 | issue = 5869 | pages = 1506–1509 | year = 2008 | doi = 10.1126/science.1153282 | pmid = 18339933 |bibcode = 2008Sci...319.1506E }}</ref> and the EE Times article was later corrected. In 2003, a group of researchers published results on high-temperature superconductivity in [[palladium hydride]] (PdH_x: x>1)<ref name=Tripodi2003>Physica C 388-389 (2003) p.571-572 [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVJ-4841319-6&_user=6686075&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=6686075&md5=4dfe98dac323e63bf7c743350a8c482e Possibility of high temperature superconducting phases in PdH,]</ref> and an explanation in 2004.<ref name=Tripodi2004>Physica C 408-410 (2004) p.350-352 [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVJ-4C2R52T-1R&_user=6686075&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000057973&_version=1&_urlVersion=0&_userid=6686075&md5=4045c898f999547289c4a57826419636 Superconductivity in PdH: phenomenological explanation]</ref> In 2007 the same group published results suggesting a superconducting transition temperature of 260&nbsp;K.<ref name=Tripodi2007>{{cite journal |title=A review of high temperature superconducting property of PdH system, |volume=21 |issue=18&19 |year=2007 |pages=3343–3347 |url=http://www.worldscinet.com/cgi-bin/details.cgi?id=pii:S0217979207044524&type=html |doi=10.1142/S0217979207044524 |author=Tripodi et al |location=[[International Journal of Modern Physics B]] |last2=Di Gioacchino |first2=Daniele |last3=Vinko |first3=Jenny Darja |journal=International Journal of Modern Physics B |bibcode = 2007IJMPB..21.3343T }}</ref> The superconducting critical temperature increases as the density of hydrogen inside the palladium lattice increases. This work has not been corroborated by other groups. In 2000, while extracting electrons from diamond during his 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 {{nowrap|10^-6&nbsp;mbar}} vacuum.<ref>{{cite journal |url = http://rtn.elektronika.lt/mi/0304/2prins.pdf |journal = [[Semiconductor Science and Technology]] |vol = 18 |year = 2003 |title = The diamond–vacuum interface: II. Electron extraction from n-type diamond: evidence for superconduction at room temperature |first1 = JF |last1 = Prins |doi = 10.1088/0268-1242/18/3/319|bibcode = 2003SeScT..18S.131P }}</ref> He developed and self-published a theory using a [[Eugene Wigner|Wigner]]-type mechanism as opposed to the [[Cooper pair]] mechanism to explain the phenomenon.<ref>{{cite book |chapterurl = http://www.cathodixx.com/pdfs/SingleMechanism.pdf |title = The Physics Delusion |chapter = 23. The Mechanism |publisher = Sage Wise 66 (Pty) Ltd |date = September 2010 |isbn = 978-0-620-48462-6 |author = Johan Prins}}</ref> {{As of|2010}}, this work had not been corroborated. ==Theories== Theoretical work by Neil Ashcroft predicted that solid [[metallic hydrogen]] at extremely high pressure (~500 GPa) should become superconducting at approximately room-temperature because of its extremely high [[speed of sound]] and expected strong [[coupling (physics)|coupling]] between the conduction electrons and the lattice vibrations ([[phonons]]).<ref name=Ashc1968> {{cite journal |author = N. W. Ashcroft |title = Metallic Hydrogen: A High-Temperature Superconductor? |year = 1968 |journal = [[Physical Review Letters]] |volume = 21 |issue=26 |pages = 1748–1749 |doi = 10.1103/PhysRevLett.21.1748 |bibcode = 1968PhRvL..21.1748A }}</ref> This prediction is yet to be experimentally verified, as yet the pressure to achieve metallic hydrogen is not known but may be of the order of 500 GPa. In 1964, William A. Little proposed the possibility of high temperature superconductivity in organic polymers.<ref>{{cite journal |author = W. A. Little |title = Possibility of Synthesizing an Organic Superconductor |year = 1964 |journal = Physical Review |volume = 134 |pages = A1416-A1424 |doi = 10.1103/PhysRev.134.A1416|bibcode = 1964PhRv..134.1416L }}</ref> This proposal is based on the [[exciton]]-mediated electron pairing, as opposed to [[phonon]]-mediated pairing in [[BCS theory]]. ==References== {{Reflist}} {{DEFAULTSORT:Room-Temperature Superconductor}} [[Category:Superconductors]] [[ja:室温超伝導]] http://www.technologyreview.com/view/429203/room-temperature-superconductivity-found-in/'