High-throughput discovery and electron-doping tuning of superconducting ternary lithium borides

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 F m 3 ¯ m and F 4 ¯ 3 m phases of Li 2 M B ( M = 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 C ≥ 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 4 ¯ 3 m 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 F m 3 ¯ m phase, Dirac points near the Fermi level are observed in the M = 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.