Superconductivity in scandium borocarbide with orbital hybridization
Superconductivity in scandium borocarbide with orbital hybridization
复制标题
轨道杂化硼碳化钪的超导性
DOI：
10.1088/2053-1591/abc4b3
复制
发表时间：
2020
影响因子：
2.3
通讯作者：
Luo J. L.
中科院分区：
文献类型：
--
作者：
Wu W.;Li Y. J.;Zhang J. H.;Yu Z. H.;Liu Z. Y.;Zheng P.;Yang H. X.;Dong C.;Liu K.;Xiang T.;Luo J. L.
Exploration of superconductivity in light element compounds has drawn considerable attention because those materials can easily realize the high T C superconductivity, such as LnNi2B2C (T C = 17 K), MgB2 (T C = 39 K), and very recently super-hydrides under pressure (T C = 250 K). Here we report the discovery of bulk superconductivity at 7.8 K in scandium borocarbide Sc20BC27 with a tetragonal lattice which structure changes based on the compound of Sc3C4 with very little B doping. Magnetization and specific heat measurements show bulk superconductivity. An upper critical field of H c2(0) ∼ 8 T is determined. Low temperature specific-heat shows that this system is a BCS fully gapped s-wave superconductor. Electronic structure calculations demonstrate that compared with Sc3C4 there are more orbital overlap and hybridization between Sc 3d electrons and 2p electrons of C-C(B)-C fragment in Sc20BC27, which form a new electric conduction path of Sc-C(B)-Sc. Those changes influence the band structure at the Fermi level and may be the reason of superconductivity in Sc20BC27.
