Correlation between superconductivity and antiferromagnetism in Rb<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mrow><mml:mn>0.8</mml:mn></mml:mrow></mml:msub></mml:math>Fe<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mrow><mml:mn>2</mml:mn><mml:mo>−</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub></mml:math>Se<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:

Gu, Dachun; Sun, Liling; Wu, Qi; Zhang, Chao; Guo, Jing; Gao, Peiwen; Wu, Yue; Dong, Xianlin; Dai, Xi; Zhao, Zhongxian

doi:10.1103/physrevb.85.174523

Cited by 18 publications

(26 citation statements)

References 28 publications

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“…On the contrary, in FeAs-based superconductors doping on Fe site is beneficial as it induces superconductivity in compounds such as Ba(Fe,Co) 2 As 2 [8]. In FeCh-11 materials, doping on Ch site enhances superconductivity [16,17], whereas it has an opposite trend in AFeCh-122 where S and Te doping decreases T c [68,129]. However, the suppression of superconductivity is far less strong when compared to doping on Fe site.…”

Section: Features Of µ 0 H C2 (T ) In Iron Chalcogenide Superconductorsmentioning

confidence: 83%

Iron chalcogenide superconductors at high magnetic fields

Lei

Wang

et al. 2012

Science and Technology of Advanced Materials

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Iron chalcogenide superconductors have become one of the most investigated superconducting materials in recent years due to high upper critical fields, competing interactions and complex electronic and magnetic phase diagrams. The structural complexity, defects and atomic site occupancies significantly affect the normal and superconducting states in these compounds. In this work we review the vortex behavior, critical current density and high magnetic field pair-breaking mechanism in iron chalcogenide superconductors. We also point to relevant structural features and normal-state properties.

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Section: Features Of µ 0 H C2 (T ) In Iron Chalcogenide Superconductorsmentioning

confidence: 83%

Iron chalcogenide superconductors at high magnetic fields

Lei

Wang

et al. 2012

Science and Technology of Advanced Materials

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“…While the T C initially rises with this narrowing of the bandwidth, it eventually reaches a maximum before lowering again, forming a dome-like structure while the bandwidth continues to shrink together with the increase of the density of states at E F , towards the metal-insulator transition (MIT) [34]. For the A x Fe 2−y Se 2 system, further isovalent substitution of Se by the bigger Te atoms has indeed been revealed to reduce T C , demonstrating a superconducting dome similar to that of the A 3 C 60 [35], showing that moderate electron correlation as seen in the narrowing of the quasiparticle bandwidth is important for superconductivity until a threshold is reached where the system approaches the MIT [36].…”

mentioning

confidence: 92%

Bandwidth and Electron Correlation-Tuned Superconductivity inRb0.8Fe2(Se1−z
Yi
¹
,
Wang
²
,
Kemper
³

et al. 2015
Phys. Rev. Lett.
18
1
18
1
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We present a systematic angle-resolved photoemission spectroscopy study of the substitutiondependence of the electronic structure of Rb0.8Fe2(Se1−zSz)2 (z = 0, 0.5, 1), where superconductivity is continuously suppressed into a metallic phase. Going from the non-superconducting Rb0.8Fe2S2 to superconducting Rb0.8Fe2Se2, we observe little change of the Fermi surface topology, but a reduction of the overall bandwidth by a factor of 2. Hence for these heavily electron-doped iron chalcogenides, we have identified electron correlation as explicitly manifested in the quasiparticle bandwidth to be the important tuning parameter for superconductivity, and that moderate correlation is essential to achieving high TC .PACS numbers: 74.25.Jb, 74.70.Xa, In the current study of iron-based superconductors, one of the challenges is to understand the superconductivity (T C ∼ 30 K) in the heavily electron-doped iron chalcogenides A x Fe 2−y Se 2 (A = alkali metal) despite their lack of the ubiquitous Fermi surface (FS) nesting conditions previously thought to be a key for the ironpnictide superconductivity [1][2][3]. Moreover, an antiferromagnetically ordered insulating phase with a spin S = 2 and moment as large as 3.3 µ B [4] has been discovered to exist in proximity to superconductivity in A x Fe 2−y Se 2 . Subsequently, many theories have been proposed to understand the superconductivity in A x Fe 2−y Se 2 from a strong coupling approach [5][6][7], where superconductivity appears in proximity to a Mott phase. Thereby, it becomes important to determine experimentally the key tuning parameters for superconductivity in this family.However, one of the initial challenges has been to control the stoichiometry of the material composition in the growth process, preventing a systematic way to tune the T C . More recently, it has been shown that substitution of selenium by sulfur can tune and suppress T C continuously [8,9], offering a pathway for systematically studying the emergence of superconductivity in this family.In this Letter, we use angle-resolved photoemission spectroscopy (ARPES) to study the Rb 0.8 Fe 2 (Se 1−z S z ) 2 (z = 0, 0.5, 1) series, where the replacement of selenium by sulfur progressively turns a 32 K superconductor into a non-superconducting metallic phase. In the electronic structure, we observe minimal changes in the FS topology, accompanied by a small change of the total charge carrier concentration.More significantly, from Rb 0.8 Fe 2 S 2 to Rb 0.8 Fe 2 Se 2 , the overall quasiparticle bandwidth is observed to decrease by a factor of 2, signaling a dramatic change in electron correlations. This can be understood by considering the bigger size of the selenium atoms compared to sulfur, which expands the lattice, hence increasing the overall electron correlations. Our results show that for the alkali-metal doped iron chalcogenides, electron correlations as controlled by the bandwidth, rather than charge carrier doping or FS topology, is the important tuning parameter for superconductivity, and moderate correla...

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“…In addition, a stripe AF order that has the same magnetic structure as that in the iron pnictide parent materials albeit with additional rhombic iron vacancy order (x ≈ 1.0, y ≈ 1.5, referred to as the 234 phase) and a phase with one Fe vacancy in eight Fe atoms(x ≈ 0.5, y ≈ 1.75, referred to as the 278 phase) have also been proposed as possible parent compounds 24,25 . The complex mixture of phases is due to the difficulty in controlling the stoichiometry and separating the effect of many factors including the iron content, carrier doping, and isovalent substitution on the formation of the various phases and the T c s [26][27][28][29] . Thus, it is crucial to identify the true parameters that tune between these phases including those responsible for inducing superconductivity, and then to compare these parameters between the iron pnictides and cuprates to elucidate the general relationship between magnetism and superconductivity.…”

Section: Introductionmentioning

confidence: 99%

Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides

Wang

Bourret-Courchesne

et al. 2016

Phys. Rev. B

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The complex interdigitated phases have greatly frustrated attempts to document the basic features of the superconductivity in the alkali metal intercalated iron chalcogenides. Here, using elastic neutron scattering, energy-dispersive x-ray spectroscopy, and resistivity measurements, we elucidate the relations of these phases in RbxFeySe2−zSz. We find: i) the iron content is crucial in stabilizing the stripe antiferromagnetic (AF) phase with rhombic iron vacancy order (y ≈ 1.5), the block AF phase with √ 5 × √ 5 iron vacancy order (y ≈ 1.6), and the iron vacancy-free phase (y ≈ 2); ii) the iron vacancy-free superconducting phase (z = 0) evolves into an iron vacancy-free metallic phase with sulfur substitution (z > 1.5) due to the progressive decrease of the electronic correlation strength. Both the stripe AF phase and the block AF phase are Mott insulators. The iron-rich compounds (y > 1.6) undergo a first order transition from an iron vacancy disordered phase at high temperatures into the √ 5 × √ 5 iron vacancy ordered phase and the iron vacancy-free phase below Ts. Our data demonstrate that there are miscibility gaps between these three phases. The existence of the miscibility gaps in the iron content is a key to understanding the relationship between these complicated phases.

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Correlation between superconductivity and antiferromagnetism in Rb0.8Fe2−ySe

Cited by 18 publications

References 28 publications

Iron chalcogenide superconductors at high magnetic fields

Iron chalcogenide superconductors at high magnetic fields

Bandwidth and Electron Correlation-Tuned Superconductivity inRb0.8Fe2(Se1−z
Yi
¹
,
Wang
²
,
Kemper
³

et al. 2015
Phys. Rev. Lett.
18
1
18
1
View full text Add to dashboard Cite

Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides

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Correlation between superconductivity and antiferromagnetism in Rb0.8Fe2−ySe

Cited by 18 publications

References 28 publications

Iron chalcogenide superconductors at high magnetic fields

Iron chalcogenide superconductors at high magnetic fields

Bandwidth and Electron Correlation-Tuned Superconductivity inRb0.8Fe2(Se1−zYi1, Wang2, Kemper3 et al. 2015Phys. Rev. Lett.181181View full textAdd to dashboardCite

Elucidating the magnetic and superconducting phases in the alkali metal intercalated iron chalcogenides

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Product

Resources

About

Bandwidth and Electron Correlation-Tuned Superconductivity inRb0.8Fe2(Se1−z
Yi
¹
,
Wang
²
,
Kemper
³

et al. 2015
Phys. Rev. Lett.
18
1
18
1
View full text Add to dashboard Cite