新型超导体的晶体结构表征

关于准二维结构超导体的研究取得了大量研究成果，而对于准一维结构超导体的研究则鲜有报道，并且已经发现的几种准一维结构超导体的临界温度（Tc）都很低，仅有几开尔文。最近报道的一系列准一维结构铬基超导体具有非常规超导的物理性质以及可能的自选三重态的电子配对机制，非常引人关注，其晶体结构则与包括Chevrel相的钼硫族化合物超导体非常相似。然而，类似结构的MoAs型化合物则至今没有发现。通过详细优化固相反应条件，成功合成了一种新型三元MoAs基化合物Cs2Mo3As3, 其晶格结构属于非中心对称六方晶系. 扫描电子显微镜形貌表征显示其晶粒为细长线状，进一步确认了其准一维的晶体结构特征。电阻、磁化率以及比热测量表明样品具有体超导电性。
长期以来，由于半导体工业的需求，人们对单质硅中砷原子的掺杂、扩散机制、分子动力学规律等进行了大量而详实的研究，但是对于硅化合物中的砷掺杂却一直鲜有报道。为实现Mo5Si3的电子型载流子掺杂调控，详细研究了该体系中Si位的As掺杂合成条件，发现在1600度高温下通过固相反应可以成功实现As对Mo5Si3的掺杂调控。Si原子在Mo5Si3中占有4a（Si1）和8h（Si2）两个位置，而As原子有选择性地占据了Si2的位置，从而导致As对Si的最大掺杂比例为1/3。通过一系列的高质量样品制备和掺杂研究，他们发现As掺杂引入的电子将该体系从拓扑半金属转变为超导体，在最大掺杂含量的化学相Mo5Si2As中超导Tc 达到最高7.7 K。相关研究成果已发表在Inorganic Chemistry 61, 10267 (2022), 并被编辑以“Arsenic Introduces Superconductivity in a Silicide”为题目选为期刊封面论文。
本数据集包含发现的两种新型超导体Cs2Mo3As3和Mo5Si2As的晶体结构数据原始文件，由马尔文帕纳科公司生产的X射线衍射仪（型号:XPert Powder）测试获取。

Extensive research achievements have been made in superconductors with quasi-two-dimensional structures, while studies on quasi-one-dimensional (quasi-1D) superconductors are rarely reported. Moreover, the critical temperatures (Tc) of several reported quasi-1D superconductors are extremely low, only a few Kelvin. A series of recently reported quasi-1D chromium-based superconductors exhibit unconventional superconducting physical properties and a potential spin-triplet electron pairing mechanism, attracting considerable attention. Their crystal structures are highly similar to those of molybdenum chalcogenide superconductors including the Chevrel phase. However, no MoAs-type compounds with analogous structures have been discovered to date. By thoroughly optimizing the solid-state reaction conditions, a novel ternary MoAs-based compound Cs₂Mo₃As₃ was successfully synthesized, whose lattice structure belongs to the non-centrosymmetric hexagonal crystal system. Scanning electron microscopy (SEM) morphological characterization reveals that its grains are slender wire-like, further confirming its quasi-1D crystal structural features. Measurements of electrical resistance, magnetic susceptibility, and specific heat demonstrate that the samples exhibit bulk superconductivity.

For a long time, driven by the demands of the semiconductor industry, extensive and detailed studies have been conducted on arsenic atom doping, diffusion mechanisms, and molecular dynamics rules in elemental silicon, yet there have been few reports on arsenic doping in silicon compounds. To achieve electron-type carrier doping modulation of Mo₅Si₃, the synthesis conditions for As doping at Si sites in this system were systematically investigated. It was found that As doping modulation of Mo₅Si₃ can be successfully realized via solid-state reaction at a high temperature of 1600 °C. Si atoms in Mo₅Si₃ occupy two crystallographic sites: 4a (Si1) and 8h (Si2). As atoms selectively occupy the Si2 site, leading to a maximum As-to-Si doping ratio of 1/3. Through a series of high-quality sample preparation and doping studies, it was found that the electrons introduced by As doping transform this system from a topological semimetal into a superconductor, with the superconducting Tc reaching a maximum of 7.7 K in the phase with the maximum doping content, Mo₅Si₂As. The relevant research results have been published in *Inorganic Chemistry* 61, 10267 (2022), and were selected as the journal cover paper by the editors with the title "Arsenic Introduces Superconductivity in a Silicide".

This dataset contains the raw crystal structure data files of two newly discovered superconductors, Cs₂Mo₃As₃ and Mo₅Si₂As, which were measured using an X-ray diffractometer (model: XPert Powder) manufactured by Malvern Panalytical.