Materials
·
2025
·Vol. 18
·期 9
·2108
·
IF 3.2
Yangzhou Wang,Qianshuo Wang,Yanhao Dong,Jin Wang,Shu Chen,Zihan Wang,Fei Chen,Guixin Cao,Wei Ren,Jie Li,Wen Wan
Multiband and nodal-like superconductivity (SC) with s- + d-wave pairing symmetry have implied that tetragonal iron sulphide (FeS) is a distinctive testbed for exploring unexpected electronic correlations. In particular, the low-moment disordered static magnetism originating from the Fe moment leads to the possibility of the coexistence of magnetic orders (MOs) in the superconducting ground state via the tuning of electronic configurations. Here, guided by density functional theory (DFT) calculations, we found that slightly substitutionally doped chromium (Cr) atoms in tetragonal FeS single crystals can induce both considerable d-orbital reconstruction around the Fermi surface and a local magnetic moment of 2.4µBat each doping site, which could highly modulate the SC ground states of the host. On this basis, a clear magnetic transition and reduced anisotropy of SC were experimentally observed. In particular, SC can survive with a doping content below 0.05. This coexistence of SC and MOs suggests strong spin correlations between Cr dopants and the host through exchange coupling. Further, an electronic temperature-related phase diagram of FeS with Cr doping contents from 0 to 0.07 is also provided. These results demonstrate that the continuous injection of local moments can be a controllable method to use to tune collective orders in unconventional iron-based superconductors.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Zhongnan Guo,Fan Sun,Danilo Puggioni,Yubo Luo,Xiaotong Li,Xiuquan Zhou,Duck Young Chung,Erjian Cheng,Shiyan Li,James M. Rondinelli,Wenxia Yuan,Mercouri G. Kanatzidis
Metal cluster compounds have garnered renewed interest in the search for novel superconductors and topological semimetals owing to structural instabilities of metal-cluster geometries and broken symmetries. Here we synthesized needle-like crystals of the V-cluster-based quasi-one-dimensional (Q1D) materials AV3Q3Oδ (A = K, Rb, Cs, Q = Se, Te) which can also be viewed as being composed of parallel nanowires. We examine how changes in their average and local structure control their electronic properties. All compounds crystallize in the TlFe3Te3-type structure (P63/m space group) with infinite (V3Q3)− double-walled columnar chains separated by A+ cations. Our single-crystal and synchrotron powder diffraction studies indicate oxygen atoms partially occupy the center site of the V6 octahedral metal cluster cages in KV3Te3O0.33, RbV3Te3O0.32, and CsV3Te3O0.35, whereas KV3Se3 is structurally oxygen-free. Our synchrotron X-ray pair distribution function (PDF) analyses indicate that the oxygen-free V6 cluster octahedra in KV3Se3 are highly distorted perpendicular to the chain direction even at room temperature, reducing the symmetry of the average structure from hexagonal P63/m to monoclinic P21/m. Our theoretical calculation supports this P21/m distortion and suggests the structure further distorts to P21 or P21/c at lower temperatures. In contrast, the oxygen-centered V-cluster in KV3Te3O0.33 exhibits a V3-triangle-trimerization along the chain direction. This feature is discernible from the local PDF and is consistent with lattice dynamical calculations based on density functional theory. Resistivity measurements indicate that KV3Se3 exhibits metallic behavior, whereas a dramatic metal–semiconductor–metal transition emerges in KV3Te3O0.33, RbV3Te3O0.32, and CsV3Te3O0.35 because of oxygen disorder and changes in local structure captured from our electronic structure analyses of the Fermi surface. Our investigation of the AV3Q3Oδ family demonstrates the importance of understanding local changes in structure driven by electronic instabilities, which can guide the search for new quantum materials in other low-dimensional cluster-compound materials.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
Biomimetics
·
2023
·Vol. 8
·期 1
·104
·
IF 4.5
Lili Zhang,Jitang Zhang,Aijiao Xu,Zhiping Lin,Zongpeng Wang,Wenwu Zhong,Shijie Shen,Guangfeng Wu
The electrocatalytic hydrogen evolution activity of transition metal sulfide heterojunctions are significantly increased when compared with that of a single component, but the mechanism behind the performance enhancement and the preparation of catalysts with specific morphologies still need to be explored. Here, we prepared a Co9S8/MoS2heterojunction with microsphere morphology consisting of thin nanosheets using a facile two-step method. There is electron transfer between the Co9S8and MoS2of the heterojunction, thus realizing the redistribution of charge. After the formation of the heterojunction, the density of states near the Fermi surface increases, thed-band center of the transition metal moves downward, and the adsorption of both water molecules and hydrogen by the catalyst are optimized. As a result, the overpotential of Co9S8/MoS2is superior to that of most relevant electrocatalysts reported in the literature. This work provides insight into the synergistic mechanisms of heterojunctions and their morphological regulation.Keywords:heterojunction;thin nanosheets;Co9S8;MoS2;electrocatalyst;hydrogen evolution reaction
研究领域:
材料科学
·
电化学
·
催化
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Physics
·
2017
·Vol. 14
·期 2
·134-139
·
IF 22.806
Du Zengyi,Yang Xiong,Altenfeld Dustin,Gu Qiangqiang,Yang Huan,Eremin Ilya,Hirschfeld Peter J.,Mazin Igor I.,Lin Hai,Zhu Xiyu,Wen Hai-Hu
Iron pnictides are the only known family of unconventional high-temperature superconductors besides cuprates. Until recently, it was widely accepted that superconductivity is driven by spin fluctuations and intimately related to the fermiology, specifically, hole and electron pockets separated by the same wavevector that characterizes the dominant spin fluctuations, and supporting order parameters (OP) of opposite signs1,2. This picture was questioned after the discovery of intercalated or monolayer form of FeSe-based systems without hole pockets, which seemingly undermines the basis for spin-fluctuation theory and the idea of a sign-changing OP3,4,5,6,7,8,9,10,11. Using the recently proposed phase-sensitive quasiparticle interference technique, here we show that in LiOH-intercalated FeSe compound the OP does change sign, albeit within the electronic pockets. This result unifies the pairing mechanism of iron-based superconductors with or without the hole Fermi pockets and supports the conclusion that spin fluctuations play the key role in electron pairing.
研究领域:
物理学
·
超导性
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）