论文标题
一个新的准二维超导体父级化合物NAMN $ _6 $ bi $ _5 $带有较低的抗铁磁过渡温度
A new quasi-one-dimensional superconductor parent compound NaMn$_6$Bi$_5$ with lower antiferromagnetic transition temperatures
论文作者
论文摘要
基于MN的超导体很少见，最近在准二维KMN $ _6 $ _6 $ bi $ _5 $中，[Mn $ _6 $ _6 $ bi $ _5 $] - 高压下的列。在这里，我们报告了新发现的准中二维NAMN $ _6 $ bi $ _5 $单晶的合成，磁性特性，电阻率和比热容量。与其他AMN $ _6 $ bi $ _5 $（a = k，rb和cs）相比，NAMN $ _6 $ bi $ _5 $具有较大的列内BI-BI债券长度，这可能会导致两个解耦的抗fiferromagnetic在47.3 k和52.3 k中的相对较低的过渡。 NAMN $ _6 $ bi $ _5 $一个更合适的平台，用于探索基于MN的超导体。在低温下观察到各向异性电阻率和非弗米液体行为。热容量测量表明，NAMN $ _6 $ bi $ _5 $与AMN $ _6 $ bi $ _5 $（a = k和rb）的Debye温度相似，而Sommerfeld系数异常大。使用第一原理计算，与其他AMN $ _6 $ _6 $ _5 $ _5 $（a = k，rb和cs）化合物相比，NAMN $ _6 $ bi $ _5 $的状态密度和在费米水平附近的异常增强。
Mn-based superconductor is rare and recently reported in quasi-one-dimensional KMn$_6$Bi$_5$ with [Mn$_6$Bi$_5$]-columns under high pressure. Here we report the synthesis, magnetic properties, electrical resistivity, and specific heat capacity of the newly-discovered quasi-one-dimensional NaMn$_6$Bi$_5$ single crystal. Compared with other AMn$_6$Bi$_5$ (A = K, Rb, and Cs), NaMn$_6$Bi$_5$ has larger intra-column Bi-Bi bond length, which may result in the two decoupled antiferromagnetic transitions at 47.3 K and 52.3 K. The relatively lower antiferromagnetic transition temperatures make NaMn$_6$Bi$_5$ a more suitable platform to explore Mn-based superconductors. Anisotropic resistivity and non-Fermi liquid behavior at low temperature are observed. Heat capacity measurement reveals that NaMn$_6$Bi$_5$ has similar Debye temperature with those of AMn$_6$Bi$_5$ (A = K and Rb), whereas the Sommerfeld coefficient is unusually large. Using first-principles calculations, the quite different density of states and an unusual enhancement near the Fermi level are observed for NaMn$_6$Bi$_5$, when compared with those of other AMn$_6$Bi$_5$ (A = K, Rb, and Cs) compounds.
