Superconducting properties of single-crystalline A_{x}Fe_{2-y}Se_{2} (A=Rb, K) studied using muon spin spectroscopy

Abstract

We report on the superconducting properties of A_{x}Fe_{2-y}Se_{2} (A = Rb, K) single crystals studied with the muon spin relaxation or rotation (\muSR) technique. At low temperatures, close to 90% of the sample volumes exhibit large-moment magnetic order which impedes the investigation of their superconducting properties by \muSR. On the other hand, about 10% of the sample volumes remain paramagnetic and clearly show a superconducting response. The temperature dependence of the superconducting carrier density was analyzed within the framework of a single s-wave gap scenario. The zero-temperature values of the in-plane magnetic penetration depths λ_{ab}(0) = 258(2) and 225(2) nm and the superconducting gaps Δ(0) = 7.7(2) and 6.3(2) meV have been determined for A = Rb and K, respectively. The microscopic coexistence and/or phase separation of superconductivity and magnetism is discussed.

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References in corpus (12)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
• Superconductivity at 32 K in single crystal Rb${}_{0.78}$Fe${}_2$Se${}_{1.78}$}
• Nanoscale phase separation in the iron chalcogenide superconductor K0.8Fe1.6Se2 as seen via scanning nanofocused x-ray diffraction
• Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe(2)As(2)
• Superconductivity and Magnetic Properties of high-quality single crystals of $A_x$Fe${}_2$Se${}_2$ ($A$ = K and Cs)
• Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2
• 77Se NMR Investigation of the K(x)Fe(2-y)Se(2) High Tc Superconductor (Tc=33K)
• Magnetic-superconducting phase boundary of SmFeAsO${}_{1-x}$F${}_x$ studied via muon spin rotation: Unified behavior in a pnictide family
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Room temperature antiferromagnetic order in superconducting X_yFe_{2-x}Se_ 2, (X= Rb, K): a powder neutron diffraction study
• Magnetic-field tuned anisotropy in superconducting Rb(x)Fe(2-y)Se(2)

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