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RESEARCH PRODUCT
Pressure-restored superconductivity in Cu-substituted FeSe
Iwan A. TroyanChang-hai WangSergey A. MedvedevJennifer SchmittVadim KsenofontovMikhail EremetsClaudia FelserFrederick CasperA. J. WilliamsRobert J. CavaLeslie M. SchoopTaras Palasyuksubject
DiffractionSuperconductivityMaterials scienceCondensed matter physicsDopingCondensed Matter PhysicsCopper dopingElectronic Optical and Magnetic MaterialsMetalLattice constantElectrical resistivity and conductivityvisual_artvisual_art.visual_art_mediumAmbient pressuredescription
Copper doping of FeSe destroys its superconductivity at ambient pressure, even at low doping levels. Here we report the pressure-dependent transport and structural properties of Fe${}_{1.01\ensuremath{-}x}$Cu${}_{x}$Se with 3$%$ and 4$%$ Cu doping and find that the superconductivity is restored. Metallic resistivity behavior, absent in Cu-doped FeSe, is also restored. At the low pressure of 1.5 GPa, superconductivity is seen at 6 K for 4$%$ Cu doping, somewhat lower than the 8 K ${T}_{c}$ of undoped FeSe. ${T}_{c}$ reaches its maximum of 31.3 K at 7.8 GPa, lower than the maximum superconducting temperature in the undoped material under pressure (${T}_{c}$ max of 37 K) but still very high. X-ray diffraction shows that applied pressure decreases the lattice parameter in the basal plane, counteracting the structural effect of Cu doping, providing a possible explanation for the restoration of the superconductivity.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-11-08 | Physical Review B |