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

中文翻译：

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兆巴压力下非包合物三元硼氢化镧中的 105 K 以上超导性


氢化物是实现室温超导性的有希望的候选者，但将稳定压力降低到兆巴以下仍然是一项艰巨的挑战。在这项研究中，我们通过将非金属元素B引入到La-H体系中，形成牢固的B-H共价键，降低了稳定超导相所需的压力，成功合成了三元硼氢化镧。电输运测量证实了超导性的存在，其临界温度 (T _c ) 在 90 GPa 下高达 106 K，零电阻和外部磁场下的 T _c 位移证明了这一点场地。 X 射线衍射和传输测量将超导化合物鉴定为 LaB ₂ H ₈ ，一种非笼形氢化物，其晶体结构在低至半兆巴 (59 GPa) 的压力下保持稳定。在亚兆巴压力范围内稳定超导化学计量的 LaB ₂ H ₈ 标志着在多元氢化物中寻求高温 _c 超导性方面取得了实质性进展，使我们更加接近至环境压力条件。