Single crystals of Sn₄Sb₃ with mm size have been obtained for the first time via a Sn flux method. Structural refinements confirm its trigonal structure with the centrosymmetric $R\bar{3}m$ space group. The unit cell consists of ordered [Sn–Sb–Sn–Sb–Sn–Sb–Sn] lamellae stacked along the c-axis, in which Sn is found to exhibit mixed valence states of 0 and 2+. Below 1.47 K, single crystalline Sn₄Sb₃ becomes a weakly coupled, fully gapped superconductor. In contrast to polycrystalline samples, the resistive transition of Sn₄Sb₃ crystals coincides well with the specific-heat jump, which supports that grain boundaries are responsible for the higher resistive T_c in the former case. Theoretical calculations show that the density of states at the Fermi level are mainly contributed by Sn and Sb 5p orbitals and almost unaffected by the spin-orbit interaction. Our study lays a foundation for experimental investigations of the predicted topological properties in this intermetallic compound.

通过Sn助熔剂法首次获得了mm尺寸的Sn ₄ Sb ₃单晶。结构改进证实了其具有中心对称性的三角结构$\mathrm{电阻}\bar{3}米$空间群。晶胞由沿c轴堆叠的有序 [Sn-Sb-Sn-Sb-Sn-Sb-Sn] 薄片组成，其中发现 Sn 表现出 0 和 2+ 的混合价态。低于 1.47 K，单晶 Sn ₄ Sb ₃变成弱耦合、完全带隙的超导体。与多晶样品相反，Sn ₄ Sb ₃晶体的电阻转变与比热跳跃非常吻合，这支持晶界是前一种情况下较高电阻T _c的原因。理论计算表明，费米能级态密度主要由Sn和Sb 5 p贡献轨道，几乎不受自旋轨道相互作用的影响。我们的研究为该金属间化合物的预测拓扑性质的实验研究奠定了基础。