Synthesis and post-annealing effects of alkaline-metal-ethylenediamine-intercalated superconductors Ax(C2H8N2)yFe2-zSe2 (A = Li, Na) with Tc = 45 K

Abstract

New iron-based intercalation superconductors Ax(C2H8N2)yFe2-zSe2 (A = Li, Na) with Tc = 45 K have successfully been synthesized via intercalation of dissolved alkaline metal in ethylenediamine. The c-axis lengths of Ax(C2H8N2)yFe2-zSe2 (A = Li, Na) are 20.74(7) Å and 21.9(1) Å, respectively, and are about 50 % larger than that of KxFe2Se2, indicating that not only alkaline metal but also ethylenediamine is intercalated between the Se-Se layers of FeSe. It seems that the high-Tc of Ax(C2H8N2)yFe2-zSe2 (A = Li, Na) is caused by the possible two-dimensional electronic structure due to the large c-axis length. Through the post-annealing in an evacuated glass tube, it has been found that Tc decreases with increasing post-annealing temperature and that deintercalation of EDA from the as-intercalated sample takes place at low temperatures below 250 °C.

arXiv comment7 pages, 6 figures

References in corpus (5)

• Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
• Pressure evolution of low-temperature crystal structure and bonding of 37 K $T_c$ FeSe superconductor
• Enhancement of superconducting transition temperature of FeSe by intercalation of a molecular spacer layer
• Observation of superconductivity at 30 K~46 K in AxFe2Se2 (A = Li, Na, Ba, Sr, Ca, Yb, and Eu)
• Superconductivity at Tc = 44 K in LixFe2Se2(NH3)y

Cited by in corpus (29)

• Using Gap Symmetry and Structure to Reveal the Pairing Mechanism in Fe-based Superconductors
• On the Remarkable Superconductivity of FeSe and its Close Cousins
• Phase diagram of (Li1-xFex)OHFeSe: a bridge between iron selenide and arsenide superconductors
• Superconductivity and phase instability of NH3-free Na-intercalated FeSe1-zSz
• The intercalation chemistry of layered iron chalcogenide superconductors
• High Tc via spin fluctuations from incipient bands: application to monolayers and intercalates of FeSe
• New intercalation superconductor Lix(C6H16N2)yFe2-zSe2 with a very large interlayer-spacing and Tc = 38 K
• Enhancement of Tc by point-like disorder and anisotropic gap in FeSe
• Unified picture of the doping dependence of superconducting transition temperatures in alkali metal/ammonia intercalated FeSe
• Extreme anisotropy and anomalous transport properties of heavily electron doped Lix(NH3)yFe2Se2 single crystals
• New Superconducting Phase of Li${}_x$(C${}_6$H${}_{16}$N${}_2$)${}_y$Fe${}_{2-z}$Se${}_2$ with $T_{\text{c}}$ = 41 K Obtained through the Post-Annealing
• Unconventional density waves and superconductivities in Fe-based superconductors and other strongly correlated electron systems
• 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
• Enhanced superconducting transition temperature in hyper-interlayer-expanded FeSe despite the suppressed electronic nematic order and spin fluctuations
• New Lithium- and Diamines-Intercalated Superconductors Li${}_x$(C${}_2$H${}_8$N${}_2$)${}_y$TiSe${}_2$ and Li${}_x$(C${}_6$H${}_{16}$N${}_2$)${}_y$TiSe${}_2$
• Ab-initio perspective on structural and electronic properties of iron-based superconductors
• Emergence of magnetism and controlling factors of superconductivity in Li/Na-ammonia co-intercalated FeSe1-zTez
• Basic electronic properties of iron selenide under variation of structural parameters
• Superconductivity at 44.4 K achieved by intercalating EMIM+ into FeSe
• 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
• Robustness of superconductivity to structural disorder in Sr${}_{0.3}$(NH${}_2$)${}_y$(NH${}_3$)${}_{1-y}$Fe${}_2$Se${}_2$
• Synthesis of New Lithium- and Monoamine-Intercalated Superconductors Li${}_x$(C${}_n$H${}_{2n+3}$N)${}_y$Fe${}_{1-z}$Se ($n$ = 6, 8, 18) with the Dramatically Expanded Interlayer Spacing
• Doping effects on electronic states in electron-doped FeSe: Impact of self-energy and vertex corrections
• $\mathrm{L}{\mathrm{i}}_{\mathrm{x}}({\mathrm{C}}_5{\mathrm{H}}_5\mathrm{N}{)}_{\mathrm{y}}\mathrm{F}{\mathrm{e}}_{2-\mathrm{z}}\mathrm{S}{\mathrm{e}}_2$: a defect resilient expanded-lattice high-temperature superconductor
• Importance of Fermi surface and magnetic interactions for the superconducting dome in electron doped FeSe intercalates
• In-situ topotactic chemical reaction for spectroscopies
• 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
• New Lithium- and Diamine-Intercalated Superconductors Lix(CnH2n+4N2)yMoSe2 (n = 2, 6)
• Enhanced superconductivity and moderate spin fluctuations suppressed at low energies in heavily electron-doped La1111-based superconductor