Soft chemical control of superconductivity in lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe

Abstract

Hydrothermal synthesis is described of layered lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe (x ~ 0.2; 0.02 < y < 0.15) with a wide range of iron site vacancy concentrations in the iron selenide layers. This iron vacancy concentration is revealed as the only significant compositional variable and as the key parameter controlling the crystal structure and the electronic properties. Single crystal X-ray diffraction, neutron powder diffraction and X-ray absorption spectroscopy measurements are used to demonstrate that superconductivity at temperatures as high as 40 K is observed in the hydrothermally synthesised samples when the iron vacancy concentration is low (y < 0.05) and when the iron oxidation state is reduced slightly below +2, while samples with a higher vacancy concentration and a correspondingly higher iron oxidation state are not superconducting. The importance of combining a low iron oxidation state with a low vacancy concentration in the iron selenide layers is emphasised by the demonstration that reductive post-synthetic lithiation of the samples turns on superconductivity with critical temperatures exceeding 40 K by displacing iron atoms from the Li1-xFex(OH) reservoir layer to fill vacancies in the selenide layer

arXiv comment7 pages supplementary material available from Journal, Inorganic Chemistry 2015

References in corpus (14)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Enhancement of superconducting transition temperature of FeSe by intercalation of a molecular spacer layer
• Structure determination and coexistence of superconductivity and antiferromagnetic order in (Li0.8Fe0.2)OHFeSe
• Observation of superconductivity at 30 K~46 K in AxFe2Se2 (A = Li, Na, Ba, Sr, Ca, Yb, and Eu)
• Two-dome structure in electron-doped iron arsenide superconductors
• Superconducting Phases in Potassium-Intercalated Iron Selenides
• Coexistence of 3d-ferromagnetism and superconductivity in [(Li(1-x)Fex)OH](Fe(1-y)Liy)Se
• NMR Study in the Iron-Selenide Rb0.74Fe1.6Se2: Determination of the Superconducting Phase as Iron Vacancy-Free Rb0.3Fe2Se2
• Phase relations in K_xFe_{2-y}Se_2 and the structure of superconducting K_xFe_2Se_2 via high-resolution synchrotron diffraction
• Superconductivity at Tc = 44 K in LixFe2Se2(NH3)y
• Cation vacancy order in the K0.8+xFe1.6-ySe2 system: five-fold cell expansion accommodates 20% tetrahedral vacancies
• The gradual destruction of magnetism in the superconducting family NaFe(1-x)CoxAs
• Structure and composition of the superconducting phase in alkali iron selenide K${}_y$Fe${}_{1.6+x}$Se${}_2$

Cited by in corpus (46)

• The key ingredients of the electronic structure of FeSe
• (Li0.84Fe0.16)OHFe0.98Se superconductor: Ion-exchange synthesis of large single crystal and highly two-dimensional electron properties
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Strong $(\pi ,0)$ spin fluctuations in $\beta$-FeSe observed by neutron spectroscopy
• Strong anisotropy in nearly ideal-tetrahedral superconducting FeS single crystals
• Magnetic interactions in iron superconductors: A review
• The intercalation chemistry of layered iron chalcogenide superconductors
• Gate-tuned Superconductor-Insulator transition in (Li,Fe)OHFeSe
• Superconductivity and magnetism in Iron Sulfides Intercalated by Metal Hydroxides
• Ultrafast Quasiparticle Dynamics and Electron-Phonon Coupling in (Li0.84Fe0.16)OHFe0.98Se
• The preparation and phase diagrams of (${}^7$Li${}_{1-x}$Fe${}_x$OD)FeSe and (Li${}_{1-x}$Fe${}_x$OH)FeSe superconductors
• Superconductivity and Nematic Fluctuations in a model of FeSe monolayers: A Determinant Quantum Monte Carlo Study
• [(Li0.8Fe0.2)OH]FeS and the ferromagnetic superconductors [(Li0.8Fe0.2)OH]Fe(S1-xSex) (0<x<1)
• Proximity induced superconductivity within the insulating (Li${}_{0.84}$Fe${}_{0.16}$)OH layers in (Li${}_{0.84}$Fe${}_{0.16}$)OHFe${}_{0.98}$Se
• Neutron investigation of the magnetic scattering in an iron-based ferromagnetic superconductor
• Spin resonance in the superconducting state of Li${}_{1-x}$Fe${}_x$ODFe${}_{1-y}$Se observed by neutron spectroscopy
• New Alkali-Metal- and 2-Phenethylamine-Intercalated Superconductors $A_x$(C${}_8$H${}_{11}$N)${}_y$Fe${}_{1-z}$Se ($A$ = Li, Na) with the Largest Interlayer Spacings and $T_{\mathrm{c}}$ $\sim$ 40 K
• Ab-initio perspective on structural and electronic properties of iron-based superconductors
• Enhanced superconducting transition temperature in hyper-interlayer-expanded FeSe despite the suppressed electronic nematic order and spin fluctuations
• Superconductivity at 40 K in lithiation-processed [(Fe,Al)(OH)2][FeSe]1.2 with a layered structure
• Basic electronic properties of iron selenide under variation of structural parameters
• Non-trivial role of interlayer cation states in iron-based superconductors
• Charge order driven by multiple-Q spin fluctuations in heavily electron-doped iron selenide superconductors
• Realization of continuously electron doping in bulk iron selenides and identification of a new superconducting zone
• Coexistence of magnetism and superconductivity in separate layers of the iron-based superconductor Li_{1-x}Fe_{x}(OH)Fe_{1-y}Se
• Superconductivity and Intercalation Statein the Lithium-Hexamethylenediamine-Intercalated Superconductor Li${}_x$(C${}_6$H${}_{16}$N${}_2$)${}_y$Fe${}_{2-z}$Se${}_2$: Dependence on the Intercalation Temperature and Lithium Content
• Electronic phase separation in iron selenide (Li, Fe)OHFeSe superconductor system
• Two-dimensional Cs-vacancy superstructure in iron-based superconductor $C{s}_{0.8}F{e}_{1.6}S{e}_2$
• Phase shift and magnetic anisotropy induced field splitting of impurity states in (Li1-xFex)OHFeSe superconductor
• Possible pairing symmetry in the FeSe-based superconductors determined by quasiparticle interference
• Robustness of superconductivity to structural disorder in Sr${}_{0.3}$(NH${}_2$)${}_y$(NH${}_3$)${}_{1-y}$Fe${}_2$Se${}_2$
• Dispersionless orbital excitations in (Li,Fe)OHFeSe superconductors
• Pairing enhanced by local orbital fluctuations in a model for monolayer FeSe
• A disorder-sensitive emergent vortex phase identified in high-Tc superconductor (Li,Fe)OHFeSe
• Efficient Soft-Chemical Synthesis of Large van-der-Waals Crystals of the Room-Temperature Ferromagnet 1T-CrTe2
• Coexistence of localized and itinerant magnetism in intercalated iron-selenide (Li,Fe)OHFeSe
• Doping Mn into (Li1-xFex)OHFe1-ySe superconducting crystals via ion-exchange and ion-release/introduction syntheses
• Importance of Fermi surface and magnetic interactions for the superconducting dome in electron doped FeSe intercalates
• Long range magnetic order in hydroxide layer doped (Li${}_{1-x-y}$Fe${}_x$Mn${}_y$OD)FeSe
• Nearly ferromagnetic metal state in the collapsed tetragonal phase of YFe${}_2$(Ge,Si)${}_2$
• $\mathrm{L}{\mathrm{i}}_{\mathrm{x}}({\mathrm{C}}_5{\mathrm{H}}_5\mathrm{N}{)}_{\mathrm{y}}\mathrm{F}{\mathrm{e}}_{2-\mathrm{z}}\mathrm{S}{\mathrm{e}}_2$: a defect resilient expanded-lattice high-temperature superconductor
• In-situ visualization of local distortions in the high-$T_c$ molecule-intercalated $L{i}_x(C_5{H}_{5}N{)}_{y}F{e}_{2-z}S{e}_2$ superconductor
• Effects of Chemical Pressure on Superconductivity in Electrochemically Intercalated (TMA)yFe2(Se1-xSx)2 (TMA = Tetramethylammonium)
• Spin correlations in the parent phase of Li${}_{1-x}$Fe${}_x$ODFeSe
• Nodeless multigap superconductivity in organic-ion-intercalated (tetrabutyl~ammonium)${}_{0.3}$FeSe
• Superconductivity of 30.4 K and its Reemergence under Pressure in Fe1.11Se Synthesized via Ion-exchange and De-intercalation Reaction