Electronic phase separation in iron selenide (Li, Fe)OHFeSe superconductor system

Abstract

The phenomenon of phase separation into antiferromagnetic (AFM) and superconducting (SC) or normal-state regions has great implication for the origin of high-temperature (high-Tc) superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the Tc of (Li, Fe)OHFeSe superconductor is questioned. Here we report a systematic study on a series of (Li, Fe)OHFeSe single crystal samples with Tc up to ~41 K. We observe an evident drop in the static magnetization at Tafm ~125 K, in some of the SC (Tc < ~38 K, cell parameter c < ~9.27 Å) and non-SC samples. We verify that this AFM signal is intrinsic to (Li, Fe)OHFeSe. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal (below Tafm) or SC (below Tc) state in (Li, Fe)OHFeSe. We explain such coexistence by electronic phase separation, similar to that in high-Tc cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of (Li, Fe)OHFeSe, particularly it is never observed in the SC samples of Tc > ~38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. It is suggested that the microscopic static phase separation reaches vanishing point in high-Tc (Li, Fe)OHFeSe, by the occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as Tafm reported previously for a (Li, Fe)OHFeSe (Tc ~42 K) single crystal. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-Tc superconductivity.

arXiv comment13 pages, 5 figures

References in corpus (26)

• Magnetic-field-induced charge-stripe order in the high temperature superconductor YBa2Cu3Oy
• Structure determination and coexistence of superconductivity and antiferromagnetic order in (Li0.8Fe0.2)OHFeSe
• Inhomogeneity of charge density wave order and quenched disorder in a high Tc superconductor
• Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor
• Coexistence of static magnetism and superconductivity in SmFeAsO1-xFx as revealed by muon spin rotation
• Microstructure and Fe-vacancy ordering in the KFexSe2 superconducting system
• Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe(2)As(2)
• Common Electronic Origin of Superconductivity in (Li,Fe)OHFeSe Bulk Superconductor and Single-Layer FeSe/SrTiO3 Films
• Electronic identification of the actual parental phase of KxFe2-ySe2 superconductor and its intrinsic mesoscopic phase separation
• Coexistence of 3d-ferromagnetism and superconductivity in [(Li(1-x)Fex)OH](Fe(1-y)Liy)Se
• (Li0.84Fe0.16)OHFe0.98Se superconductor: Ion-exchange synthesis of large single crystal and highly two-dimensional electron properties
• Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe${}_2$As${}_2$, (Sr,Na)Fe${}_2$As${}_2$ and CaFe${}_2$As${}_2$
• Surface electronic structure and isotropic superconducting gap in (Li${}_{0.8}$Fe${}_{0.2}$)OHFeSe
• Soft chemical control of superconductivity in lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe
• Microscopic co-existence of superconductivity and magnetism in Ba1-xKxFe2As2
• Phase diagram of (Li1-xFex)OHFeSe: a bridge between iron selenide and arsenide superconductors
• Feshbach resonances and mesoscopic phase separation near a quantum critical point in multiband FeAs-based superconductors
• Reemergence of high-Tc superconductivity in the (Li1-xFex)OHFe1-ySe under high pressure
• Antiferromagnetic order in epitaxial FeSe films on SrTiO3
• The preparation and phase diagrams of (${}^7$Li${}_{1-x}$Fe${}_x$OD)FeSe and (Li${}_{1-x}$Fe${}_x$OH)FeSe superconductors
• Structure of spin excitations in heavily electron-doped Li0.8Fe0.2ODFeSe superconductors
• Effects of magnetic dopants in (Li${}_{0.8}$M${}_{0.2}$OH)FeSe (M = Fe, Mn, Co): a density-functional theory study using band unfolding technique
• Neutron investigation of the magnetic scattering in an iron-based ferromagnetic superconductor
• Low-energy spin excitations in Li(0.8)Fe(0.2)ODFeSe superconductor studied with inelastic neutron scattering
• Superconductivity emerging from an electronic phase separation in the charge ordered phase of RbFe${}_2$As${}_2$
• Ab-initio Studies of (Li${}_{0.8}$Fe${}_{0.2}$)OHFeSe Superconductors: Revealing the Dual Roles of Fe${}_{0.2}$ in Structural Stability and Charge Transfer

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