La2Rh 3+δ Sb4: a new ternary superconducting rhodium-antimonide
La2Rh 3+δ Sb4: a new ternary superconducting rhodium-antimonide
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DOI：
10.1088/2752-5724/ac972f
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
Kangqiao Cheng;W. Xie;S. Zou;H. Bu;J. Bao;Zengwei Zhu;Hanjie Guo;C. Cao;Yongkang Luo
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文献类型：
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作者：
Kangqiao Cheng;W. Xie;S. Zou;H. Bu;J. Bao;Zengwei Zhu;Hanjie Guo;C. Cao;Yongkang Luo
含铑化合物为探索具有超导性（SC）和其他奇妙的电子相关效应的新材料提供了一个肥沃的操场。用Bi助熔剂法合成了一种新的三元铑锑化物La 2 Rh 3+δ Sb 4（δ Sb 1/8）。它的晶体结构为类Pr 2 Ir 3Sb 4斜方晶系，空间群为Pnma（No.62）。晶体结构表现为RhSb_4和RhSb_5的二维多面体网络沿着B轴堆叠，La原子嵌入这些网络的空腔中。能带结构计算证实它是一种多带金属，在费米能级上具有van-Hove类奇异性，态密度主要为Rh-4d和Sb-5 p特征。计算还表明，多余的Rh作为电荷掺杂剂。在该材料中观察到了超导现象，其起始转变温度为Tcon ≤ 0.8K。超低温磁化率和比热测量表明它是一种s波II型超导体。我们的工作还可能暗示Ln_2Tm_3 +δ Sb_4（Ln =稀土，Tm = Rh，Ir）大家族可能拥有新的材料基础，在那里可以发现新的超导体、量子磁性和其他电子关联效应。
Rhodium-containing compounds offer a fertile playground to explore novel materials with superconductivity (SC) and other fantastic electronic correlation effects. A new ternary rhodium-antimonide La2Rh 3+δ Sb4 ( δ≈1/8 ) has been synthesized by a Bi-flux method. It crystallizes in the orthorhombic Pr2Ir3Sb4-like structure, with the space group Pnma (No. 62). The crystalline structure appears as stacking the two-dimensional RhSb4- and RhSb5-polyhedra networks along b axis, and the La atoms embed in the cavities of these networks. Band structure calculations confirm it as a multi-band metal with a van-Hove singularity like feature at the Fermi level, whose density of states are mainly of Rh-4d and Sb-5p characters. The calculations also imply that the redundant Rh acts as charge dopant. SC is observed in this material with onset transition at Tcon≈0.8 K. Ultra-low temperature magnetic susceptibility and specific heat measurements suggest that it is an s-wave type-II superconductor. Our work may also imply that the broad Ln2Tm3+δ Sb4 (Ln = rare earth, Tm = Rh, Ir) family may host new material bases where new superconductors, quantum magnetism and other electronic correlation effects could be found.