Re-emerging superconductivity at 48 kelvin in iron chalcogenides

Sun, Liling; Chen, Xiao‐Jia; Guo, Jing; Gao, Peiwen; Huang, Q.; Wang, Hangdong; Fang, Minghu; Chen, Xiaolong; Chen, Genfu; Wu, Qi; Zhang, Chao; Gu, Dachun; Dong, Xianlin; Wang, Lin; Yang, Ke; Li, Aiguo; Dai, Xi; Mao, Ho Kwang; Zhao, Zhongxian

doi:10.1038/nature10813

Cited by 309 publications

(299 citation statements)

References 21 publications

(18 reference statements)

Supporting

Mentioning

269

Contrasting

Unclassified

Order By: Relevance

“…Pressure-tuned Tc often reaches a maximum value and then drops monotonically at higher pressures [580,647]. In a recent study on iron chalcogenides [648], a second superconducting phase suddenly reemerges above 11.5 GPa, after the Tc drops from the first maximum of 32K at 1 GPa (Fig. 35).…”

Section: Superconductorsmentioning

confidence: 99%

See 1 more Smart Citation

High-pressure studies with x-rays using diamond anvil cells

2016

View full text Add to dashboard Cite

Pressure profoundly alters all states of matter. The symbiotic development of ultrahighpressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials' properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. These HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and magnetic properties of materials over a wide range of pressure-temperature conditions.

show abstract

Section: Superconductorsmentioning

confidence: 99%

“…NSC: the nonsuperconducting region above 13.2 GPa. The inset is the setup for susceptibility measurements in DACs, with a signal coil and a compensating coil (modified after [648]). …”

Section: Future Perspectivesmentioning

confidence: 99%

High-pressure studies with x-rays using diamond anvil cells

2016

View full text Add to dashboard Cite

show abstract

“…10,11) Alkali or alkaline-earth intercalation into FeSe via a liquid ammonia route has been reported to show superconductivity at T c ~44-46 K. 12,13) And a high T c is also observed in ultrathin FeSe films. 14,15) These reports imply that the superconductivity as high as 40-48 K is a potential property of the FeSe layer structure.…”

mentioning

confidence: 99%

Direct observation of microstructures on superconducting single crystals of K_xFe₂₋ _ySe₂

Tanaka

Takeya

Takano

2017

Appl. Phys. Express

View full text Add to dashboard Cite

Potassium-intercalated FeSe has been reported as a superconductor with a superconducting transition temperature (T c) of 30–48 K. However, the relationship among the surface morphology, compositional ratio, and crystal structure has not yet been clarified. This report directly reveals the correspondence among these three characteristics in single crystals with a T c onset of around 44 K by using a microsampling technique. Island-like parts on the surface of the crystals clearly exhibit the K x Fe2Se2 structure with perfect FeSe layers, which is formed in conjunction with the K2Fe4Se5 phase. This results in the appearance of the T c onset at 44 K.

show abstract

“…Detected in the 245 superconductors is the alkaline metal deficient A x Fe 2 Se 2 (x ∼ 0.3-0.6) phase embedded in √ 5 × √ 5 iron vacancy ordered superstructure [12][13][14], forming various microstructure patterns in plane [15,16] High pressure adds an additional dimension to the complex composition phase-diagram of 245 superconductors [8], offering a "clean" way to investigate the relation among various phases [18,19]. The T c has been suppressed to zero at critical pressure P c ≈ 6 GPa for A= Rb [19,20], 8 GPa for A= Cs [21], and 9 GPa for A= K and Tl-Rb superconductors [22]. In the latter study, superconductivity of a higher T c = 48 K is reported to re-emerge between 11 and 13 GPa [22].…”

mentioning

confidence: 99%

High-Pressure Single-Crystal Neutron Scattering Study of Magnetic and Fe Vacancy Orders in (Tl,Rb) ₂ Fe ₄ Se ₅ Superconductor

Ye¹,

Bao²,

Chi³

et al. 2014

Chinese Phys. Lett.

View full text Add to dashboard Cite

The magnetic and iron vacancy orders in superconducting (Tl,Rb)2Fe4Se5 single-crystals were investigated using a high-pressure neutron diffraction technique. Similar to the temperature effect, the block antiferromagnetic order gradually decreases upon increasing pressure while the Fe vacancy superstructural order remains intact before its precipitous disappearance at the critical pressure Pc =8.3 GPa. Combined with previously determined Pc for superconductivity, our phase diagram under pressure reveals the concurrence of the block AFM order, the √ 5 × √ 5 iron vacancy order and superconductivity for the 245 superconductor. A synthesis of current experimental data in a coherent physical picture is attempted.PACS numbers: 74.62. Fj, 25.40.Dn, 74.25.Ha, The recently discovered metal-intercalated iron selenide superconductors A 2 Fe 4 Se 5 (A=K, Cs, Tl-K, Rb, Tl-Rb) (245) compounds, with T c ∼ 30 K, have attracted much interest [1,2].A high transitiontemperature (T N ≈ 470-560 K) and large magnetic moment (3.3µ B /Fe) block antiferromagnetic (AFM) order exists in the superconducting samples [3][4][5]. And magnetic order-parameter experiences an anomaly when T c is approached [4,5]. The superconductors crystallize with a highly ordered √ 5 × √ 5 superstructure, in which the Fe1 site of the I4/m structure is only a few percent occupied and the Fe2 site fully occupied [4,6]. The nonsuperconducting samples at low-T also crystallize in the I4/m structure, but both Fe sites are fractionally occupied [7,8], since the numbers of the Fe vacancies in the samples and the vacant sites in the √ 5 × √ 5 pattern are mismatched. The partially ordered √ 5 × √ 5 vacancy order becomes one of three competing phases for temperature below the room temperature up to ∼ 500 K, namely, these samples are phase-separated and in the miscibility gap at ambient condition [8,9].Close to the miscibility gap, it is not surprising that the nonstoichiometric 245 superconductors often contain several phases of different space-group symmetry. It has been a complex and controversial issue to determine the sample composition of the superconductors. The KFe 1.5 Se 2 (234) of the orthorhombic Fe vacancy order has been proposed as the parent compound [10]. However, this phase is not even the ground state for KFe 1.5 Se 2 , and a partially ordered √ 5 × √ 5 vacancy superlattice is more stable at low temperature [8]. The KFe 2 Se 2 (122) of I4/mmm symmetry has also been proposed as the superconducting phase [11]. But its existence in films grown by molecular beam epitaxy method likely requires charge transfer with the substrate, and there is no trace of its existence in bulk superconducting samples [4,12]. Detected in the 245 superconductors is the alkaline metal deficient A x Fe 2 Se 2 (x ∼ 0.3-0.6) phase embedded in √ 5 × √ 5 iron vacancy ordered superstructure [12][13][14], forming various microstructure patterns in plane [15,16] High pressure adds an additional dimension to the complex composition phase-diagram of 245 superconductors [8], offering a "clea...

show abstract

Re-emerging superconductivity at 48 kelvin in iron chalcogenides

Cited by 309 publications

References 21 publications

High-pressure studies with x-rays using diamond anvil cells

High-pressure studies with x-rays using diamond anvil cells

Direct observation of microstructures on superconducting single crystals of K_xFe₂₋ _ySe₂

High-Pressure Single-Crystal Neutron Scattering Study of Magnetic and Fe Vacancy Orders in (Tl,Rb) ₂ Fe ₄ Se ₅ Superconductor

Contact Info

Product

Resources

About

Re-emerging superconductivity at 48 kelvin in iron chalcogenides

Cited by 309 publications

References 21 publications

High-pressure studies with x-rays using diamond anvil cells

High-pressure studies with x-rays using diamond anvil cells

Direct observation of microstructures on superconducting single crystals of KxFe2− ySe2

High-Pressure Single-Crystal Neutron Scattering Study of Magnetic and Fe Vacancy Orders in (Tl,Rb) 2 Fe 4 Se 5 Superconductor

Contact Info

Product

Resources

About

Direct observation of microstructures on superconducting single crystals of K_xFe₂₋ _ySe₂

High-Pressure Single-Crystal Neutron Scattering Study of Magnetic and Fe Vacancy Orders in (Tl,Rb) ₂ Fe ₄ Se ₅ Superconductor