关键词: high-through calculations, borides, superconductivity, electronic doping

Abstract: Incorporating another metal into binary metal borides has emerged as a highly effective strategy for optimizing material properties. Herein, using high-throughput calculations, we systematically investigated the structural, electronic, and superconducting properties of Fm$\overline{3}m$ and $F\overline{4}3m$ phases of Li$_{2}M$B ($M = {\rm alkaline}$ earth, 3d, and 4d metals). Our analysis of 48 Li$_{2}M$B compounds at 0-60 GPa reveals that four of them are promising superconductors with $T_{\rm C}\ge 10$ K. It is further demonstrated that substitution of different $M$ elements serves as an effective strategy for electron doping, enabling precise control of the band structure and density of states near the Fermi level for the $F\overline{4}3m$ phase. This behavior is exemplified in Li$_{2}$Sc$_{1-x}$Ti$_{x}$B ($x=0.05$-0.25), which transforms from a semiconductor into a metal and further into a superconductor with increasing Ti doping concentration. For the Fm$\overline{3}m$ phase, Dirac points near the Fermi level are observed in the $M={\rm Sc}$ and Y systems, suggesting unique electronic behavior. Our work provides deep insight into the superconducting mechanisms of lithium-based borides and offers guidance for the targeted design of novel boride superconductors.

Key words: high-through calculations, borides, superconductivity, electronic doping