Structure, superconductivity, and magnetism in Rb1-xFe1.6Se2-zSz

Abstract

The single-crystal growth, stoichiometry, and structure of Rb1-xFe2-ySe2-zSz crystals with substitution of Se by S are reported. The variation of the magnetic and thermodynamic parameters of samples was studied by differential-scanning calorimetry, magnetic susceptibility, conductivity, and specific heat. The experimental results are discussed within a T-z phase diagram, which includes vacancy-ordered and vacancy-disordered antiferromagnetic (AFM), superconducting (SC), and non-superconducting phases. The structural study revealed change in the local environment of the Fe tetrahedrons depending on substitution: a reduction of the Fe-Fe and Fe-Ch(chalcogen) bond lengths and a tendency for the six out of eight bond angles to approach values for a regular tetrahedron suggesting a reduction of structural distortions with substitution. With increasing substitution, a lowering of the superconducting transition temperature Tc was observed; the percolation threshold for the SC state is located at the substitution z = 1.2. The SC state was found to coexist with the AFM state that persists in all samples independent of substitution. The temperature of the transition into the AFM state TN shows a monotonous decrease indicating a weakening of the AFM interactions with increasing substitution. The AFM phase exhibits an iron-vacancy-ordered structure below the structural transition at Ts. The temperature Ts shows a non-monotonous variation: a decrease with increasing z up to 1.3, followed by an increase for further increasing z. The suppression of the superconductivity with substitution is accompanied by a significant reduction of the density of states at the Fermi energy and a weakening of the electronic correlations in the studied system.

arXiv comment32 pages, 22 figures

References in corpus (42)

• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure
• Phase Diagram and High Temperature Superconductivity at 65 K in Tuning Carrier Concentration of Single-Layer FeSe Films
• Superconductivity at 27 K in tetragonal FeSe under high pressure
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• 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
• Why Does Undoped FeSe Become A High Tc Superconductor Under Pressure?
• A Novel Large Moment Antiferromagnetic Order in K0.8Fe1.6Se2 Superconductor
• Reemerging superconductivity at 48 K across quantum criticality in iron chalcogenides
• Superconductivity at 32 K in single crystal Rb${}_{0.78}$Fe${}_2$Se${}_{1.78}$}
• The Unexpected Properties of Alkali Metal Iron Selenide Superconductors
• Synthesis and crystal growth of Cs0.8(FeSe0.98)2: a new iron-based superconductor with Tc=27K
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• Superconductivity at 32K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals
• Transport properties of the new Fe-based superconductor KxFe2Se2 (Tc = 33 K)
• On the Structure of Vacancy Ordered Superconducting Alkali Metal Iron Selenide
• NMR Study in the Iron-Selenide Rb0.74Fe1.6Se2: Determination of the Superconducting Phase as Iron Vacancy-Free Rb0.3Fe2Se2
• Transport properties and anisotropy of Rb0.8Fe2Se2 single crystals
• Phase relations in K_xFe_{2-y}Se_2 and the structure of superconducting K_xFe_2Se_2 via high-resolution synchrotron diffraction
• Superconductivity and Magnetic Properties of high-quality single crystals of $A_x$Fe${}_2$Se${}_2$ ($A$ = K and Cs)
• Structure, magnetic order and excitations in the 245 family of Fe-based superconductors
• Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2
• Phase Diagram of KxFe2-ySe2-zSz and the Suppression of its Superconducting State by an Fe2-Se/S Tetrahedron Distortion
• Nanoscale layering of antiferromagnetic and superconducting phases in Rb2Fe4Se5
• Intrinsic Percolative Superconductivity in KxFe2-ySe2 Single Crystals
• Anisotropic magnetism, superconductivity, and the phase diagram of Rb(1-x)Fe(2-y)Se2
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Orbital-selective metal-insulator transition and gap formation above Tc in superconducting Rb1-xFe2-ySe2
• Crystal structure, physical properties and superconductivity in $A_x$Fe${}_2$Se${}_2$ single crystals
• The role of 245 phase in alkaline iron selenide superconductors revealed by high pressure studies
• Intrinsic crystal phase separation in antiferromagnetic superconductor RbyFe2-xSe2: a diffraction study
• Interplay between Superconductivity and Magnetism in Rb0.8Fe1.6Se2 under Pressure
• Superconductivity and magnetism in RbxFe2-ySe2: Impact of thermal treatment on mesoscopic phase separation
• Identification of prototypical Brinkman-Rice Mott physics in a class of iron chalcogenides superconductors
• Temperature and pressure evolution of the crystal structure of Ax(Fe1-ySe)2 (A = Cs, Rb, K) studied by synchrotron powder diffraction
• Bandwidth and Electron Correlation-Tuned Superconductivity in Rb${}_{0.8}$Fe${}_2$(Se${}_{1-z}$S${}_z$)${}_2$
• Two spatially separated phases in semiconducting Rb${}_{0.8}$Fe${}_{1.5}$S${}_2$
• Interplay of the electronic and lattice degrees of freedom in A_{1-x}Fe_{2-y}Se_{2} superconductors under pressure
• High-pressure study of superconducting and non-superconducting single crystals of the same nominal composition Rb0.8Fe2Se2
• Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides
• Tuning orbital-selective correlation effects in superconducting Rb${}_{0.75}$Fe${}_{1.6}$Se${}_{2-z}$S${}_z$