Here we report the high-pressure synthesis of a series of lanthanum–yttrium ternary hydrides obtained at pressures of 170–196 GPa via the laser heating of P6₃/mmc La–Y alloys with ammonia borane. As a result, we discovered several novel compounds: cubic hexahydride (La,Y)H₆ and decahydrides (La,Y)H₁₀ with a maximum critical temperature T_C ∼ 253 K and an extrapolated upper critical magnetic field B_C2(0) of up to 135 T at 183 GPa. The current–voltage measurements show that the critical current density J_C in (La,Y)H₁₀ is 12–27.7 kA/mm² at 4.2 K, which is comparable with that of commercial superconducting wires such as NbTi and Nb₃Sn. (La,Y)H₆ and (La,Y)H₁₀ are among the first examples of ternary high-T_C superconducting hydrides. Our experiments show that part of metal atoms in the structures of recently discovered $\mathit{Im}\overline{3}m$-YH₆ and $\mathit{Fm}\overline{3}m$-LaH₁₀ can be replaced with lanthanum (∼70%) and yttrium (∼25%), respectively, with the formation of unique ternary superhydrides containing metal-encapsulated cages La@H₂₄ and Y@H₃₂, which are specific for $\mathit{Im}\overline{3}m$-LaH₆ and $\mathit{Fm}\overline{3}m$-YH₁₀. This work demonstrates that hydrides, unstable in pure form such as LaH₆ and YH₁₀, may nevertheless be stabilized at relatively low pressures in solid solutions with superhydrides having the desired structure.

在这里，我们报告了 通过用氨硼烷对P 6 ₃ /mmc La-Y 合金进行激光加热，在 170-196 GPa 的压力下获得的一系列镧-钇三元氢化物的高压合成。结果，我们发现了几种新化合物：立方六氢化物 (La,Y)H ₆和十氢化物 (La,Y)H ₁₀具有最高临界温度T _C  ∼ 253 K 和外推上临界磁场B _C2 (0)在 183 GPa 时高达 135 T。电流-电压测量表明，(La,Y)H ₁₀中的临界电流密度J _C为 12–27.7 kA/mm ²在 4.2 K，这与商业超导线如 NbTi 和 Nb ₃ Sn相当。(La,Y)H ₆和(La,Y)H ₁₀是三元高T _C超导氢化物的第一个例子。我们的实验表明，最近发现的结构中的部分金属原子$\mathit{我是}\overline{3}米$-YH ₆和$\mathit{调频}\overline{3}米$-LaH ₁₀可以分别替换为镧（~70%）和钇（~25%），形成独特的三元超氢化物，其中包含金属封装的笼 La@H ₂₄和 Y@H ₃₂，它们是特异性的$\mathit{我是}\overline{3}米$-LaH ₆和$\mathit{调频}\overline{3}米$-YH ₁₀。这项工作表明，在具有所需结构的超氢化物的固溶体中，以纯形式不稳定的氢化物（例如 LaH ₆和 YH ₁₀）仍然可以在相对较低的压力下稳定。