Physics:Iron-based superconductor

Iron-based superconductors (FeSC) are iron-containing chemical compounds whose superconducting properties were discovered in 2006.[2][3] The first of such superconducting compounds belong to the group of oxypnictides, which was known since 1995.[4] Until 2006, however, they were in the first stages of experimentation and implementation[5] and only the semiconductive properties of these compounds were known and patented.[6] Scientific American described subsequent research as follows:
The crystalline material, known chemically as LaOFeAs, stacks iron and arsenic layers, where the electrons flow, between planes of lanthanum and oxygen. Replacing up to 11 percent of the oxygen with fluorine improved the compound – it became superconductive at 26 kelvin, the team reports in the March 19, 2008 Journal of the American Chemical Society. Subsequent research from other groups suggests that replacing the lanthanum in LaOFeAs with other rare earth elements such as cerium, samarium, neodymium and praseodymium leads to superconductors that work at 52 kelvin.[7]
Previously most high-temperature superconductors were cuprates containing copper - oxygen layers. Much of the interest in iron-based superconductors is precisely because of the differences from the cuprates, which may help lead to a theory of non-BCS-theory superconductivity.[7]
Iron-based superconductors of the group of oxypnictides were initially called ferropnictides. The crystal structure of these compounds displays conducting layers of iron and a pnictogen (typically arsenic (As) and phosphorus (P)) separated by a charge-reservoir block.[8] It has also been found that some iron chalcogens and crystallogens superconduct.[9][10]
Iron-based superconductors are classified according to their crystal structure and chemical formula into the following main families,
- 1111-type, with representative compounds LaFePO,[2] LaFeAsO,[3] SmFeAsO,[11] PrFeAsO,[12][13] and LaFeSiH.[14]
- 111-type such as LiFeAs,[15][16][17] NaFeAs,[18][19][20] and LiFeP.[21]
- 11-type FeSe[22]
- 122-type such as BaFe2As2,[23] SrFe2As2[24] and CaFe2As2[25]
Superconductivity is obtained either in the parent phases of some of these systems (e.g. LaFePO,[2] LaFeSiH,[14] and LiFeAs[15][16][17]) or by means of doping or applied pressure.[8][26][27]
Undoped β-FeSe is the simplest iron-based superconductor but with distinct properties.[22] It has a critical temperature (Tc) of 8 K at normal pressure, and 36.7 K under high pressure[28] and by means of intercalation. The combination of both intercalation and higher pressure results in re-emerging superconductivity at Tc of up to 48 K (see,[22][29] and references therein).
Compared with other families, the synthesis of the 122 compounds is relatively easy which facilitates the investigation of these systems.
| Oxypnictide | Tc (K) |
|---|---|
| LaO0.89F0.11FeAs | 26[8] |
| LaO0.9F0.2FeAs | 28.5[30] |
| CeFeAsO0.84F0.16 | 41[8] |
| SmFeAsO0.9F0.1 | 43[8][11] |
| La0.5Y0.5FeAsO0.6 | 43.1[31] |
| NdFeAsO0.89F0.11 | 52[8] |
| PrFeAsO0.89F0.11 | 52[12] |
| ErFeAsO1−y | 45[32] |
| Al-32522 (CaAlOFeAs) | 30(As), 16.6 (P)[33] |
| Al-42622 (CaAlOFeAs) | 28.3(As), 17.2 (P)[34] |
| GdFeAsO0.85 | 53.5[35] |
| BaFe1.8Co0.2As2 | 25.3[36] |
| SmFeAsO~0.85 |
| Non-oxypnictide | Tc (K) |
|---|---|
| Ba0.6K0.4Fe2As2 | 38[23] |
| Ca0.6Na0.4Fe2As2 | 26[25] |
| CaFe0.9Co0.1AsF | 22[37] |
| Sr0.5Sm0.5FeAsF | 56[38] |
| LiFeAs | 18[15][16][17] |
| NaFeAs | 9–25[18][19] |
| FeSe | <27[39][40] |
| LaFeSiH | 11[14] |
Compounds such as Sr2ScFePO3 discovered in 2009 are referred to as the '42622' family, as FePSr2ScO3.[41] Noteworthy is the synthesis of (Ca4Al2O6−y)(Fe2Pn2) (or Al-42622(Pn); Pn = As and P) using high-pressure synthesis technique. Al-42622(Pn) exhibit superconductivity for both Pn = As and P with the transition temperatures of 28.3 K and 17.1 K, respectively. The a-lattice parameters of Al-42622(Pn) (a = 3.713 Å and 3.692 Å for Pn = As and P, respectively) are smallest among the iron-pnictide superconductors. Correspondingly, Al-42622(As) has the smallest As–Fe–As bond angle (102.1°) and the largest As distance from the Fe planes (1.5 Å).[34] High-pressure technique also yields (Ca3Al2O5−y)(Fe2Pn2) (Pn = As and P), the first reported iron-based superconductors with the perovskite-based '32522' structure. The transition temperature (Tc) is 30.2 K for Pn = As and 16.6 K for Pn = P. The emergence of superconductivity is ascribed to the small tetragonal a-axis lattice constant of these materials. From these results, an empirical relationship was established between the a-axis lattice constant and Tc in iron-based superconductors.[33]
In 2009, it was shown that undoped iron pnictides had a magnetic quantum critical point deriving from competition between electronic localization and itinerancy.[42]

Properties
Similarly to superconducting cuprates, the properties of iron based superconductors change dramatically with doping. Parent compounds of FeSC are usually metals (unlike the cuprates) but, similarly to cuprates, are ordered antiferromagnetically that often termed as a spin-density wave (SDW). Some parent compounds superconduct.[2][14][15][16][17] Otherwise, superconductivity emerges upon either hole or electron doping. In general, the phase diagram is similar to the cuprates.[43]

Superconducting transition temperatures are listed in the tables (some at high pressure). BaFe1.8Co0.2As2 is predicted to have an upper critical field of 43 tesla from the measured coherence length of 2.8 nm.[36]
In 2011, Japanese scientists made a discovery which increased a metal compound's superconductivity by immersing iron-based compounds in hot alcoholic beverages such as red wine.[49][50] Earlier reports indicated that excess Fe is the cause of the bicollinear antiferromagnetic order and is not in favor of superconductivity. Further investigation revealed that weak acid has the ability to deintercalate the excess Fe from the interlayer sites. Therefore, weak acid annealing suppresses the antiferromagnetic correlation by deintercalating the excess Fe and, hence superconductivity is achieved.[51][52]
There is an empirical correlation of the transition temperature with electronic band structure: the Tc maximum is observed when some of the Fermi surface stays in proximity to Lifshitz topological transition.[43] Similar correlation has been later reported for high-Tc cuprates that indicates possible similarity of the superconductivity mechanisms in these two families of high temperature superconductors.[53]
Thin films
The critical temperature is increased further in thin-films of iron chalcogenides on suitable substrates. In 2015, a Tc of around 105–111 K was observed in thin films of iron selenide grown on strontium titanate.[54]
See also
References
- ↑ Hosono, H.; Tanabe, K.; Takayama-Muromachi, E.; Kageyama, H.; Yamanaka, S.; Kumakura, H.; Nohara, M.; Hiramatsu, H. et al. (2015). "Exploration of new superconductors and functional materials, and fabrication of superconducting tapes and wires of iron pnictides". Science and Technology of Advanced Materials 16 (3). doi:10.1088/1468-6996/16/3/033503. PMID 27877784. Bibcode: 2015STAdM..16c3503H.
- ↑ 2.0 2.1 2.2 2.3 Kamihara, Yoichi; Hiramatsu, Hidenori; Hirano, Masahiro; Kawamura, Ryuto; Yanagi, Hiroshi; Kamiya, Toshio; Hosono, Hideo (2006). "Iron-Based Layered Superconductor: LaOFeP". J. Am. Chem. Soc. 128 (31): 10012–10013. doi:10.1021/ja063355c. PMID 16881620.
- ↑ 3.0 3.1 Kamihara, Yoichi; Watanabe, Takumi; Hirano, Masahiro; Hosono, Hideo (2008). "Iron-Based Layered Superconductor La[O1−xFx]FeAs (x = 0.05–0.12) with Tc = 26 K". Journal of the American Chemical Society 130 (11): 3296–3297. doi:10.1021/ja800073m. PMID 18293989.
- ↑ Zimmer, Barbara I.; Jeitschko, Wolfgang; Albering, Jörg H.; Glaum, Robert; Reehuis, Manfred (1995). "The rate earth transition metal phosphide oxides LnFePO, LnRuPO and LnCoPO with ZrCuSiAs type structure". Journal of Alloys and Compounds 229 (2): 238–242. doi:10.1016/0925-8388(95)01672-4.
- ↑ Ozawa, T C; Kauzlarich, S M (2008). "Chemistry of layered d-metal pnictide oxides and their potential as candidates for new superconductors". Sci. Technol. Adv. Mater. 9 (3). doi:10.1088/1468-6996/9/3/033003. PMID 27877997. Bibcode: 2008STAdM...9c3003O.
- ↑ Hosono, H. et al. (2006) Magnetic semiconductor material European Patent Application EP1868215
- ↑ 7.0 7.1 "Iron Exposed as High-Temperature Superconductor". Scientific American. June 2008
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Ishida, Kenji; Nakai, Yusuke; Hosono, Hideo (2009). "To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report". Journal of the Physical Society of Japan 78 (6). doi:10.1143/JPSJ.78.062001. Bibcode: 2009JPSJ...78f2001I.
- ↑ Johannes, Michelle (2008). "The iron age of superconductivity". Physics 1: 28. doi:10.1103/Physics.1.28. Bibcode: 2008PhyOJ...1...28J. https://physics.aps.org/featured-article-pdf/10.1103/PhysRevB.78.134514.
- ↑ Bernardini, F. et al. (2018). "Iron-based superconductivity extended to the novel silicide LaFeSiH". Physical Review B 97 (10). doi:10.1103/PhysRevB.97.100504. Bibcode: 2018PhRvB..97j0504B.
- ↑ 11.0 11.1 Chen, X. H.; Wu, T.; Wu, G.; Liu, R. H.; Chen, H.; Fang, D. F. (2008). "Superconductivity at 43 K in SmFeAsO1–xFx". Nature 453 (7196): 761–762. doi:10.1038/nature07045. PMID 18500328. Bibcode: 2008Natur.453..761C.
- ↑ 12.0 12.1 Ren, Z. A.; Yang, J.; Lu, W.; Yi, W.; Che, G. C.; Dong, X. L.; Sun, L. L.; Zhao, Z. X. (2008). "Superconductivity at 52 K in iron based F doped layered quaternary compound Pr[O1−xFx]FeAs". Materials Research Innovations 12 (3): 105–106. doi:10.1179/143307508X333686. Bibcode: 2008MatRI..12..105R.
- ↑ Ren, Zhi-An; Che, Guang-Can; Dong, Xiao-Li; Yang, Jie; Lu, Wei; Yi, Wei; Shen, Xiao-Li; Li, Zheng-Cai et al. (2008). "Superconductivity and phase diagram in iron-based arsenic-oxides ReFeAsO1−δ (Re = rare-earth metal) without fluorine doping". EPL 83 (1). doi:10.1209/0295-5075/83/17002. Bibcode: 2008EL.....8317002R.
- ↑ 14.0 14.1 14.2 14.3 Bernardini, F. et al. (2018). "Iron-based superconductivity extended to the novel silicide LaFeSiH". Physical Review B 97 (10). doi:10.1103/PhysRevB.97.100504. ISSN 2469-9969. Bibcode: 2018PhRvB..97j0504B.
- ↑ 15.0 15.1 15.2 15.3 Wang, X.C.; Liu, Q.Q.; Lv, Y.X.; Gao, W.B.; Yang, L.X.; Yu, R.C.; Li, F.Y.; Jin, C.Q. (2008). "The superconductivity at 18 K in LiFeAs system". Solid State Communications 148 (11–12): 538–540. doi:10.1016/j.ssc.2008.09.057. Bibcode: 2008SSCom.148..538W.
- ↑ 16.0 16.1 16.2 16.3 Pitcher, Michael J.; Parker, Dinah R.; Adamson, Paul; Herkelrath, Sebastian J. C.; Boothroyd, Andrew T.; Ibberson, Richard M.; Brunelli, Michela; Clarke, Simon J. (2008). "Structure and superconductivity of LiFeAs". Chemical Communications (45): 5918–20. doi:10.1039/b813153h. PMID 19030538.
- ↑ 17.0 17.1 17.2 17.3 Tapp, Joshua H.; Tang, Zhongjia; Lv, Bing; Sasmal, Kalyan; Lorenz, Bernd; Chu, Paul C. W.; Guloy, Arnold M. (2008). "LiFeAs: An intrinsic FeAs-based superconductor with Tc=18 K". Physical Review B 78 (6). doi:10.1103/PhysRevB.78.060505. Bibcode: 2008PhRvB..78f0505T.
- ↑ 18.0 18.1 Chu, C.W.; Chen, F.; Gooch, M.; Guloy, A.M.; Lorenz, B.; Lv, B.; Sasmal, K.; Tang, Z.J. et al. (2009). "The synthesis and characterization of LiFeAs and NaFeAs". Physica C: Superconductivity 469 (9–12): 326–331. doi:10.1016/j.physc.2009.03.016. Bibcode: 2009PhyC..469..326C.
- ↑ 19.0 19.1 Parker, Dinah R.; Pitcher, Michael J.; Clarke, Simon J. (2008). "Structure and superconductivity of the layered iron arsenide NaFeAs". Chemical Communications 2189 (16): 2189–91. doi:10.1039/B818911K. PMID 19360189.
- ↑ Zhang, S. J.; Wang, X. C.; Liu, Q. Q.; Lv, Y. X.; Yu, X. H.; Lin, Z. J.; Zhao, Y. S.; Wang, L. et al. (2009). "Superconductivity at 31 K in the "111"-type iron arsenide superconductor Na1−xFeAs induced by pressure". EPL 88 (4). doi:10.1209/0295-5075/88/47008. Bibcode: 2009EL.....8847008Z.
- ↑ Deng, Z.; Wang, X. C.; Liu, Q. Q.; Zhang, S. J.; Lv, Y. X.; Zhu, J. L.; Yu, R. C.; Jin, C. Q. (2009). "A new "111" type iron pnictide superconductor LiFeP". EPL 87 (3). doi:10.1209/0295-5075/87/37004. Bibcode: 2009EL.....8737004D.
- ↑ 22.0 22.1 22.2 Yu. V. Pustovit; A. A. Kordyuk (2016). "Metamorphoses of electronic structure of FeSe-based superconductors (Review article)". Low Temp. Phys. 42 (11): 995–1007. doi:10.1063/1.4969896. Bibcode: 2016LTP....42..995P.
- ↑ 23.0 23.1 Rotter, Marianne; Tegel, Marcus; Johrendt, Dirk (2008). "Superconductivity at 38 K in the Iron Arsenide (Ba1−xKx)Fe2As2". Physical Review Letters 101 (10). doi:10.1103/PhysRevLett.101.107006. PMID 18851249. Bibcode: 2008PhRvL.101j7006R.
- ↑ Sasmal, K.; Lv, Bing; Lorenz, Bernd; Guloy, Arnold M.; Chen, Feng; Xue, Yu-Yi; Chu, Ching-Wu (2008). "Superconducting Fe-Based Compounds (A1−xSrx) Fe2As2 with A=K and Cs with Transition Temperatures up to 37 K". Physical Review Letters 101 (10). doi:10.1103/physrevlett.101.107007. PMID 18851250. Bibcode: 2008PhRvL.101j7007S. http://repository.ust.hk/ir/bitstream/1783.1-18311/1/PhysRevLett.101.107007.pdf.
- ↑ 25.0 25.1 Shirage, Parasharam Maruti; Miyazawa, Kiichi; Kito, Hijiri; Eisaki, Hiroshi; Iyo, Akira (2008). "Superconductivity at 26 K in (Ca1−xNax)Fe2As2". Applied Physics Express 1 (8). doi:10.1143/APEX.1.081702. Bibcode: 2008APExp...1h1702M.
- ↑ Day, C. (2009). "Iron-based superconductors". Physics Today 62 (8): 36–40. doi:10.1063/1.3206093. Bibcode: 2009PhT....62h..36D.
- ↑ Stewart, G. R. (2011). "Superconductivity in iron compounds". Rev. Mod. Phys. 83 (4): 1589–1652. doi:10.1103/revmodphys.83.1589. Bibcode: 2011RvMP...83.1589S.
- ↑ Medvedev, S.; McQueen, T. M.; Troyan, I. A.; Palasyuk, T.; Eremets, M. I.; Cava, R. J.; Naghavi, S.; Casper, F. et al. (2009). "Electronic and Magnetic Phase Diagram of β-Fe1.01Se with superconductivity at 36.7 K under pressure". Nature Materials 8 (8): 630–633. doi:10.1038/nmat2491. PMID 19525948. Bibcode: 2009NatMa...8..630M.
- ↑ Sun, Liling; Chen, Xiao-Jia; Guo, Jing; Gao, Peiwen; Huang, Qing-Zhen; Wang, Hangdong; Fang, Minghu; Chen, Xiaolong et al. (2012). "Re-emerging superconductivity at 48 kelvin in iron chalcogenides". Nature 483 (7387): 67–69. doi:10.1038/nature10813. PMID 22367543. Bibcode: 2012Natur.483...67S.
- ↑ Prakash, J.; Singh, S. J.; Samal, S. L.; Patnaik, S.; Ganguli, A. K. (2008). "Potassium fluoride doped LaOFeAs multi-band superconductor: Evidence of extremely high upper critical field". EPL 84 (5). doi:10.1209/0295-5075/84/57003. Bibcode: 2008EL.....8457003P.
- ↑ Shirage, Parasharam M.; Miyazawa, Kiichi; Kito, Hijiri; Eisaki, Hiroshi; Iyo, Akira (2008). "Superconductivity at 43 K at ambient pressure in the iron-based layered compound La1−xYxFeAsOy". Physical Review B 78 (17). doi:10.1103/PhysRevB.78.172503. Bibcode: 2008PhRvB..78q2503S.
- ↑ Shirage, Parasharam M.; Miyazawa, Kiichi; Kihou, Kunihiro; Lee, Chul-Ho; Kito, Hijiri; Tokiwa, Kazuyasu; Tanaka, Yasumoto; Eisaki, Hiroshi et al. (2010). "Synthesis of ErFeAsO-based superconductors by the hydrogen doping method". EPL 92 (5). doi:10.1209/0295-5075/92/57011. Bibcode: 2010EL.....9257011S.
- ↑ 33.0 33.1 Shirage, Parasharam M.; Kihou, Kunihiro; Lee, Chul-Ho; Kito, Hijiri; Eisaki, Hiroshi; Iyo, Akira (2011). "Emergence of Superconductivity in "32522" Structure of (Ca3Al2O5−y)(Fe2Pn2) (Pn = As and P)". Journal of the American Chemical Society 133 (25): 9630–3. doi:10.1021/ja110729m. PMID 21627302.
- ↑ 34.0 34.1 Shirage, Parasharam M.; Kihou, Kunihiro; Lee, Chul-Ho; Kito, Hijiri; Eisaki, Hiroshi; Iyo, Akira (2010). "Superconductivity at 28.3 and 17.1 K in (Ca4Al2O6−y)(Fe2Pn2) (Pn=As and P)". Applied Physics Letters 97 (17): 172506. doi:10.1063/1.3508957. Bibcode: 2010ApPhL..97q2506S.
- ↑ Yang, Jie; Li, Zheng-Cai; Lu, Wei; Yi, Wei; Shen, Xiao-Li; Ren, Zhi-An; Che, Guang-Can; Dong, Xiao-Li et al. (2008). "Superconductivity at 53.5 K in GdFeAsO1−δ". Superconductor Science and Technology 21 (8). doi:10.1088/0953-2048/21/8/082001. Bibcode: 2008SuScT..21h2001Y.
- ↑ 36.0 36.1 Yin, Yi; Zech, M.; Williams, T. L.; Wang, X. F.; Wu, G.; Chen, X. H.; Hoffman, J. E. (2009). "Scanning Tunneling Spectroscopy and Vortex Imaging in the Iron Pnictide Superconductor BaFe1.8Co0.2As2". Physical Review Letters 102 (9). doi:10.1103/PhysRevLett.102.097002. PMID 19392555. Bibcode: 2009PhRvL.102i7002Y.
- ↑ Satoru Matsuishi; Yasunori Inoue; Takatoshi Nomura; Hiroshi Yanagi; Masahiro Hirano; Hideo Hosono (2008). "Superconductivity Induced by Co-Doping in Quaternary Fluoroarsenide CaFeAsF". J. Am. Chem. Soc. 130 (44): 14428–14429. doi:10.1021/ja806357j. PMID 18842039.
- ↑ Wu, G; Xie, Y L; Chen, H; Zhong, M; Liu, R H; Shi, B C; Li, Q J; Wang, X F et al. (2009). "Superconductivity at 56 K in samarium-doped SrFeAsF". Journal of Physics: Condensed Matter 21 (14). doi:10.1088/0953-8984/21/14/142203. PMID 21825317. Bibcode: 2009JPCM...21n2203W.
- ↑ Fong-Chi Hsu et al. (2008). "Superconductivity in the PbO-type structure α-FeSe". PNAS 105 (38): 14262–14264. doi:10.1073/pnas.0807325105. PMID 18776050. Bibcode: 2008PNAS..10514262H.
- ↑ Mizuguchi, Yoshikazu; Tomioka, Fumiaki; Tsuda, Shunsuke; Yamaguchi, Takahide; Takano, Yoshihiko (2008). "Superconductivity at 27 K in tetragonal FeSe under high pressure". Appl. Phys. Lett. 93 (15): 152505. doi:10.1063/1.3000616. Bibcode: 2008ApPhL..93o2505M.
- ↑ Yates, K A; Usman, I T M; Morrison, K; Moore, J D; Gilbertson, A M; Caplin, A D; Cohen, L F; Ogino, H et al. (2010). "Evidence for nodal superconductivity in Sr2ScFePO3". Superconductor Science and Technology 23 (2). doi:10.1088/0953-2048/23/2/022001. Bibcode: 2010SuScT..23b2001Y.
- ↑ Dai, Jianhui; Si, Qimiao; Zhu, Jian-Xin; Abrahams, Elihu (2009-03-17). "Iron pnictides as a new setting for quantum criticality" (in en). Proceedings of the National Academy of Sciences 106 (11): 4118–4121. doi:10.1073/pnas.0900886106. ISSN 0027-8424. PMID 19273850. Bibcode: 2009PNAS..106.4118D.
- ↑ 43.0 43.1 43.2 A. A. Kordyuk (2012). "Iron-based superconductors: Magnetism, superconductivity, and electronic structure (Review Article)". Low Temp. Phys. 38 (9): 888. doi:10.1063/1.4752092. Bibcode: 2012LTP....38..888K.
- ↑ Luetkens, H; Klauss, H. H.; Kraken, M; Litterst, F. J.; Dellmann, T; Klingeler, R; Hess, C; Khasanov, R et al. (2009). "Electronic phase diagram of the LaO1−xFxFeAs superconductor". Nature Materials 8 (4): 305–9. doi:10.1038/nmat2397. PMID 19234445. Bibcode: 2009NatMa...8..305L.
- ↑ Drew, A. J.; Niedermayer, Ch; Baker, P. J.; Pratt, F. L.; Blundell, S. J.; Lancaster, T; Liu, R. H.; Wu, G et al. (2009). "Coexistence of static magnetism and superconductivity in SmFeAsO1−xFx as revealed by muon spin rotation". Nature Materials 8 (4): 310–314. doi:10.1038/nmat2396. PMID 19234446. Bibcode: 2009NatMa...8..310D.
- ↑ Sanna, S.; De Renzi, R.; Lamura, G.; Ferdeghini, C.; Palenzona, A.; Putti, M.; Tropeano, M.; Shiroka, T. (2009). "Competition between magnetism and superconductivity at the phase boundary of doped SmFeAsO pnictides". Physical Review B 80 (5). doi:10.1103/PhysRevB.80.052503. Bibcode: 2009PhRvB..80e2503S.
- ↑ Zhao, J; Huang, Q; de la Cruz, C; Li, S; Lynn, J. W.; Chen, Y; Green, M. A.; Chen, G. F. et al. (2008). "Structural and magnetic phase diagram of CeFeAsO1−xFx and its relation to high-temperature superconductivity". Nature Materials 7 (12): 953–959. doi:10.1038/nmat2315. PMID 18953342. Bibcode: 2008NatMa...7..953Z.
- ↑ Chu, Jiun-Haw; Analytis, James; Kucharczyk, Chris; Fisher, Ian (2009). "Determination of the phase diagram of the electron doped superconductor Ba(Fe1−xCox)2As2". Physical Review B 79 (1). doi:10.1103/PhysRevB.79.014506. Bibcode: 2009PhRvB..79a4506C.
- ↑ "Press release: Japanese scientists use alcoholic drinks to induce superconductivity". Institute of Physics. 7 March 2011. http://www.iop.org/news/11/march/page_50051.html.
- ↑ Deguchi, K; Mizuguchi, Y; Kawasaki, Y; Ozaki, T; Tsuda, S; Yamaguchi, T; Takano, Y (2011). "Alcoholic beverages induce superconductivity in FeTe1−xSx". Superconductor Science and Technology 24 (5). doi:10.1088/0953-2048/24/5/055008. Bibcode: 2011SuScT..24e5008D.
- ↑ "Red Wine, Tartaric Acid, and the Secret of Superconductivity" (in en). MIT Technology Review. March 22, 2012. https://www.technologyreview.com/s/427302/red-wine-tartaric-acid-and-the-secret-of-superconductivity/.
- ↑ Deguchi, K; Sato, D; Sugimoto, M; Hara, H; Kawasaki, Y; Demura, S; Watanabe, T; Denholme, S J et al. (2012). "Clarification as to why alcoholic beverages have the ability to induce superconductivity in Fe1+dTe1−xSx". Superconductor Science and Technology 25 (8). doi:10.1088/0953-2048/25/8/084025. Bibcode: 2012SuScT..25h4025D.
- ↑ A. A. Kordyuk (2018). "Electronic band structure of optimal superconductors: from cuprates to ferropnictides and back again (Review Article)". Low Temp. Phys. 44 (6): 477–486. doi:10.1063/1.5037550. Bibcode: 2018LTP....44..477K.
- ↑ Ge, JF; Liu, ZL; Liu, C; Gao, CL; Qian, D; Xue, DK; Liu, Y; Jia, JF (2014). "Superconductivity above 100K in single-layer FeSe films on doped SrTiO3". Nat. Mater. 14 (3): 285–9. doi:10.1038/NMAT4153. PMID 25419814.
