采用高通量的第一性原理计算,从无机材料数据库AtomWork中搜索了具有窄带隙和近带边平坦带的热电和超导材料候选化合物.我们重点研究了在费米能级附近具有高态密度的AgIn $_{5}$ Se $_{8}$。采用熔融慢冷法成功地合成了AgIn $_{5}$ Se $_{8}$单晶。单晶X射线衍射分析表明,所获得的晶体是高质量的,没有缺陷。通过芯能级X射线光电子能谱学分析,根据形式电荷,确定AgIn $_{5}$ Se $_{8}$中的价态为Ag 1+、In 3+和Se 2-。在高压下使用具有硼掺杂金刚石电极的金刚石压砧单元评估电阻。虽然样品在常压下为绝缘体,电阻大于40 MΩ,但随着压力的增加,电阻显著降低,在3.4 K和52.5 GPa下发现了压力诱导超导转变。在74.0 GPa的压力下,相变温度上升到3.7 K。
英文摘要:
Candidates compounds for new thermoelectric and superconducting materials, which have narrow band gap and flat bands near band edges, were exhaustively searched by a high-throughput first-principles calculation from an inorganic materials database named AtomWork. We focused on AgIn$_{5}$Se$_{8}$ which has high density of state near the Fermi level. AgIn$_{5}$Se$_{8}$ was successfully synthesized as single crystals using a melt and slow cooling method. The single-crystal X-ray diffraction analysis revealed the obtained crystal is high quality without deficiencies. The valence states in AgIn$_{5}$Se$_{8}$ were determined to be Ag1+, In3+ and Se2- in accordance with a formal charge by the core level X-ray photoelectron spectroscopy analysis. The electrical resistance was evaluated under high pressure using a diamond anvil cell with boron-doped diamond electrodes. Although the sample was insulator with a resistance of above 40 MΩ at ambient pressure, the resistance markedly decreased with increase of the pressure, and a pressure-induced superconducting transition was discovered at 3.4 K under 52.5 GPa. The transition temperature increased up to 3.7 K under further pressure of 74.0 GPa.
Data-driven Exploration of New Pressure-induced Superconductivity in PbBi$_2$Te$_4$ with Two Transition Temperatures
采用高通量的第一性原理计算,从无机材料数据库AtomWork中搜索了具有窄带隙和近带边平坦带的热电和超导材料候选化合物。我们重点研究了PbBi $_2$ Te $_4$,它与采用同样的数据驱动方法研究的压致超导体SnBi 2 Se 4具有相似的电子能带结构和晶体结构。采用熔融慢冷法成功地合成了PbBi $_2$ Te $_4$单晶。芯能级X射线光电子能谱学分析揭示了PbBi $_2$ Te $_4$中Pb 2+、Bi 3+和Te 2-的价态。在常压下测量了PbBi $_2$ Te $_4$样品的热电性能,并在高压下使用具有掺硼金刚石电极的金刚石对顶砧单元评估了电阻率。电阻率随压力的增加而减小,在13.3GPa下的3.4K和21.7GPa下的8.4K出现了两次压力诱导超导转变。数据驱动的方法显示了加速发现新热电和超导材料的潜力。
Superconductivity in RbH$_{12}$ at low pressures: an \emph{ab initio} study
University of the Basque Country (UPV/EHU)(巴斯克大学);Centro de Física de Materiales (CFM-MPC), CSIC-UPV/EHU(材料物理中心,西班牙国家研究委员会-巴斯克大学);Donostia International Physics Center (DIPC)(圣塞巴斯蒂安国际物理中心)
Superconductivity in the orthorhombic phase of thermoelectric CsPbxBi4-xTe6 with 0.3=<x=<1.0
实验测量清楚地揭示了CsPbxBi_(4-x)Te_(6)(0.3=<x=<1.0)材料中存在体超导性,即Cs[PbmBi_(3-Te)_(5 +m)]热电系列的第一个成员,这些材料具有层状正交结构,含有无限的阴离子[PbBi_(3-Te)_(6)]-片,与Cs+阳离子隔开。电阻率、磁化率和比热随温度的变化表明,CsPb_(0.3)Bi_(3.7)Te_6在Tc=3.1K时发生超导转变,在1.8K时超导体积分数接近100%。使用像差校正STEM/TEM的结构研究揭示了与Pb有序和化学不均匀性相关的丰富多样的微观结构现象。具有最高Tc的超导材料CsPb_(0.3)Bi_(3.7)Te_(6)在a-c平面上显示出明显的有序结构,其调制波矢为q=a ~*/2+ c ~*/1.35。我们的研究表明,窄禁带半导体掺杂产生超导性是探索新型超导体的一条可行途径。
Superconductivity and Electron Correlations in Kagome Metal LuOs3B2
Southwest Jiaotong University(西南交通大学);Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交大李政道研究所);Shanghai Jiao Tong University(上海交通大学);Zhejiang University(浙江大学);Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering(福建省先进强磁场超导材料与工程协同创新中心);Fujian Normal University(福建师范大学)
High-pressure synthesis of superconducting Sn$_{3}$S$_{4}$ using diamond anvil cell with boron-doped diamond heater
高压技术在广泛的研究领域开辟了功能材料的探索。在已建立的金刚石对顶砧室中,用掺硼金刚石加热器和输运测量终端进行了立方Sn $_{3}$ S $_{4}$超导体的高压合成。X射线衍射和拉曼光谱表明,在减压过程中,Sn $_{3}$ S $_{4}$相在P>5 GPa的压力范围内是稳定的。在金刚石压砧单元中的传输测量终端检测合成的Sn $_{3}$ S $_{4}$中的金属性质和超导性,在5.6 GPa下具有13.3 K的最大起始转变温度。所观察到的压力-T $_{c}$关系与从第一性原理计算得到的关系是一致的。在Sn $_{3}$ S $_{4}$中观察到的超导电性开启了在高温高压条件下的进一步材料探索。
Possible Enhancement of Superconductivity in Ambient-Pressure La$_3$Ni$_2$O$_7$ Thin Film
Southern University of Science and Technology(南方科技大学);Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(粤港澳大湾区量子科学中心);State Key Laboratory of Quantum Functional Materials, Department of Physics, and Guangdong Basic Research Center of Excellence for Quantum Science, Southern University of Science and Technology (SUSTech)(南方科技大学量子功能材料国家重点实验室、物理系及广东省基础科研卓越中心)
Coexistence of Superconductivity and Antiferromagnetism in Topological Magnet MnBi2Te4 Films
The Pennsylvania State University(宾夕法尼亚州立大学);Paul Scherrer Institute(保罗谢尔研究所);National Institute of Standards and Technology(美国国家标准与技术研究院);National High Magnetic Field Laboratory(国家高磁场实验室)
Superconductivity in imbalanced bilayer Hubbard model: enhanced $d$-wave and weakened $s^\pm$-wave pairing
School of Physical Science and Technology, Soochow University(苏州大学物理科学与技术学院);Jiangsu Key Laboratory of Frontier Material Physics and Devices, Soochow University(苏州大学前沿材料物理与器件江苏省重点实验室)
Interface-Induced Superconductivity in Magnetic Topological Insulator-Iron Chalcogenide Heterostructures
The Pennsylvania State University(宾夕法尼亚州立大学);Rutgers University(罗格斯大学);University of Washington(华盛顿大学);Chinese Academy of Sciences(中国科学院);Materials Research Institute, The Pennsylvania State University(宾夕法尼亚州立大学材料研究所);National High Magnetic Field Laboratory(国家高磁场实验室);Paul Scherrer Institute(保罗谢尔研究所);National Institute of Standards and Technology(美国国家标准与技术研究院)