Superconductivity in Co-Layered LaCoSi
Zhengwen He, Rongjin Huang, Kaiyao Zhou, Ye Liu, Shibin Guo, Yuzhu Song, Zhongnan Guo, Shu‐Xian Hu, Lunhua He, Q. Huang, Laifeng Li, Jingyan Zhang, Shouguo Wang, Jiangang Guo, Xianran Xing, Jun Chen
Abstract
It is known that few Co-based superconducting compounds have been found compared with their Fe- or Ni-based counterparts. In this study, we have found superconductivity of 4 K in the LaCoSi compound for the first time. The combined analysis of neutron and synchrotron X-ray powder diffractions reveals that LaCoSi exhibits an isostructure with the known Fe-based LiFeAs superconductor, which is the first "111" Co-based superconductor. First-principles calculation shows that LaCoSi presents a quasi-two-dimensional band structure that is also similar to that of LiFeAs. The small structural distortion may be more conducive to the emergence of superconductivity in the LaCoSi compound, which provides a direction for finding new Co-based superconducting compounds.