论文标题
mo $ _6 $ ga $ _ {31} $ endohedral cluster超导体
Mo$_6$Ga$_{31}$ endohedral cluster superconductor
论文作者
论文摘要
报告了Mo $ $ _6 $ ga $ _ {31} $ Endoheohedral cluster超导体的合成，晶体和电子结构以及物理特性。该化合物具有两个晶体学修饰，即单斜和三斜胶，其中相同的{mo $ _ {12} $ ga $ _ {62} $}构建单元分别是垂直的或彼此的代码。 Mo $ $ _6 $ ga $ _ {31} $具有与状态相同的电子密度的单斜结构结构，在费米级别显示高峰。这两种修饰本质上都存在于散装标本中。由于接近效应，大量mo $ _6 $ ga $ _ {31} $在零磁场中的临界温度为8.2 k的临界温度下表现出单个超导过渡。在零温度下为7.8 t的上部临界场显示相对于Werthamer-Helfand-Honenberg的预测，显示出明显的增强。因此，热容量测量表明，在超导状态下的强电子偶联，其比率为$2δ（0）/（k_bt_c）= 4.5 $，其中2 $δ（0）$是零温度下的完整超导间隙。
Synthesis, crystal and electronic structure, and physical properties of the Mo$_6$Ga$_{31}$ endohedral cluster superconductor are reported. The compound has two crystallographic modifications, monoclinic and triclinic, in which the same {Mo$_{12}$Ga$_{62}$} building units are perpendicular or codirectional to each other, respectively. Monoclinic and triclinic structures of Mo$_6$Ga$_{31}$ possess qualitatively the same electronic density of states showing a high peak at the Fermi level. Both modifications are inherently present in the bulk specimen. Due to the proximity effect, bulk Mo$_6$Ga$_{31}$ exhibits single superconducting transition at the critical temperature of 8.2 K in zero magnetic field. The upper critical field, which is 7.8 T at zero temperature, shows clear enhancement with respect to the Werthamer-Helfand-Honenberg prediction. Accordingly, heat capacity measurements indicate strong electron-phonon coupling in the superconducting state with the large ratio of $2Δ(0)/(k_BT_c)=4.5$, where 2$Δ(0)$ is the full superconducting gap at zero temperature.
