https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=27167718&retmode=xml&tool=Litmetric&email=readroberts32@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09 271677182018031620181113
2045-232262016May11Scientific reportsSci RepNew superconductor LixFe1+δSe (x ≤ 0.07, Tc up to 44 K) by an electrochemical route.25624256242562410.1038/srep25624The superconducting transition temperature (Tc) of tetragonal Fe1+δSe was enhanced from 8.5 K to 44 K by chemical structure modification. While insertion of large alkaline cations like K or solvated lithium and iron cations in the interlayer space, the [Fe2Se2] interlayer separation increases significantly from 5.5 Å in native Fe1+δSe to >7 Å in KxFe1-ySe and to >9 Å in Li1-xFex(OH)Fe1-ySe, we report on an electrochemical route to modify the superconducting properties of Fe1+δSe. In contrast to conventional chemical (solution) techniques, the electrochemical approach allows to insert non-solvated Li(+) into the Fe1+δSe structure which preserves the native arrangement of [Fe2Se2] layers and their small separation. The amount of intercalated lithium is extremely small (about 0.07 Li(+) per f.u.), however, its incorporation results in the enhancement of Tc up to ∼44 K. The quantum-mechanical calculations show that Li occupies the octahedrally coordinated position, while the [Fe2Se2] layers remain basically unmodified. The obtained enhancement of the electronic density of states at the Fermi level clearly exceeds the effect expected on basis of rigid band behavior.AlekseevaAnastasia MAMDepartment of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.MPG-MSU Partner Group, Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.DrozhzhinOleg AOADepartment of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.MPG-MSU Partner Group, Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.DosaevKirill AKADepartment of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.MPG-MSU Partner Group, Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.AntipovEvgeny VEVDepartment of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.ZakharovKonstantin VKVDepartment of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia.VolkovaOlga SOSDepartment of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia.ChareevDmitriy ADAInstitute of Experimental Mineralogy, Russian Academy of Sciences, 142432 Chernogolovka, Russia.VasilievAlexander NANDepartment of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia.KozCevriyeCMax-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.SchwarzUlrichUMax-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.RosnerHelgeHMax-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.GrinYuriYMax-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.engJournal ArticleResearch Support, Non-U.S. Gov't20160511
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