Superconductivity above 105 K in Nonclathrate Ternary Lanthanum Borohydride below Megabar Pressure

• DOI: 10.1021/jacs.3c14205
• Publication Date: 2024-05-09T13:42:04Z
• Authors: Xiaoxu Song; Xiaokuan Hao; Xudong Wei; Xin-Ling He; Hanyu Liu; Liang Ma; Guangtao Liu; Hongbo Wang; Jingyu Niu; Shaojie Wang; Yanpeng Qi; Zhongyuan Liu; Wentao Hu; Bo Xu; Lin Wang; Guoying Gao; Yongjun Tian
• Keywords: Lanthanum; Borohydride

Hydrides are promising candidates for achieving room-temperature superconductivity, but a formidable challenge remains in reducing the stabilization pressure below megabar. In this study, we successfully synthesized ternary lanthanum borohydride by introducing nonmetallic element B into La–H system, forming robust B–H covalent bonds that lower required to stabilize superconducting phase. Electrical transport measurements confirm presence of superconductivity with critical temperature (Tc) up 106 K at 90 GPa, as evidenced zero resistance and Tc shift under an external magnetic field. X-ray diffraction identify compound LaB2H8, nonclathrate hydride, whose crystal structure stable pressures low ∼ half megabar (59 GPa). Stabilizing superconductive stoichiometric LaB2H8 submegabar regime marks substantial advancement quest high-Tc polynary hydrides, bringing us closer ambient conditions.