The search for new 3d transition metal superconductors, especially Ni-based superconductors, is of great significance for understanding the mechanism of high temperature superconductivity. Based on inorganic material database, we found a new superconductor Mo₂NiB₂ through structural design. The crystal structure of Mo₂NiB₂ was analyzed by synchrotron radiation, Mo₂NiB₂ is a superconductor with a quasi-one-dimensional structure and also a Ni-based superconductor with a new structure. We report that the Mo₂NiB₂ exhibits superconductivity of 4 K, which is a typical type Ⅱ superconductor, and the non-stoichiometric ratio of Ni sites can increase the superconducting critical temperature of Mo₂NiB₂.

寻找新型3D过渡金属超导体，特别是镍基超导体，对于理解高温超导机理具有重要意义。基于无机材料数据库，我们通过结构设计发现了一种新型超导体Mo ₂ NiB ₂。通过同步辐射分析了Mo ₂ NiB ₂的晶体结构，Mo ₂ NiB ₂是一种准一维结构的超导体，也是一种新型结构的镍基超导体。我们报道Mo ₂ NiB ₂表现出4 K的超导性，是典型的Ⅱ型超导体，并且Ni位点的非化学计量比可以提高Mo ₂ NiB ₂的超导临界温度。