AI 中文总结
本研究以氨硼烷为氢供体，在高压下通过原位激光加热合成LaH₁₀±δ薄膜，证实其高T_c超导性及时间稳定性，确立PVD薄膜前驱体为氢化物合成的可行途径。
AI 中文摘要
高压氢化物在各类超导体中保持着最高超导临界温度的纪录。目前，十氢化镧（LaH₁₀）是二元氢化物中临界温度最高的，在140-180 GPa压力区间内，其T_c约为250 K。本研究中，我们以氨硼烷（NH₃BH₃）作为氢供体，通过对元素镧薄膜进行原位激光加热，在两个金刚石对顶砧（DAC）中分别于168 GPa和176 GPa压力下合成了LaH₁₀±δ薄膜。利用同步辐射X射线衍射解析出高对称性面心立方（fcc）镧亚晶格（空间群Fm$\bar{3}$m），其晶胞参数与块体样品的前期研究结果高度吻合。我们通过电学测量证实了LaH₁₀±δ的高T_c超导性，在176 GPa压力下测得最高T_c为247 K，且在磁场中观测到超导的特征抑制现象。此外，结合衍射与电学测量结果，发现在激光加热后约300天的完整测量周期内，晶体结构与高T_c超导性均表现出优异的时间稳定性。本研究确立了采用物理气相沉积（PVD）技术制备的薄膜前驱体是合成氢化物的可行途径，为可控合成极具潜力的三元氢化物以及在金刚石对顶砧中集成微加工器件几何结构开辟了道路。
英文摘要
High-pressure hydrides hold the record for the highest superconducting critical temperatures across all classes of superconductors. Currently lanthanum decahydride, LaH$_{10}$, exhibits the highest critical temperature among binaries, with $T_c \approx$ 250 K at pressures between 140-180 GPa. Here, we report the synthesis of LaH$_{10\pmδ}$ films in two DACs at pressures of 168 GPa and 176 GPa via in situ laser heating of elemental lanthanum films with ammonia borane (NH$_3$BH$_3$) as the hydrogen donor. The high-symmetry fcc lanthanum sublattice (space group $Fm\bar3m$) is resolved using synchrotron X-ray diffraction, with unit cell parameters in excellent agreement with previous studies on bulk samples. We provide confirmation of high-$T_c$ superconductivity in LaH$_{10\pmδ}$ with highest $T_c$ of 247 K at 176 GPa evidenced in electrical measurements. The characteristic suppression of superconductivity is observed in magnetic fields. Furthermore, combined diffraction and electrical measurements reveal remarkable temporal stability of both the crystal structure and the high-$T_c$ superconductivity over the full measurement period of about 300 days post laser heating. Our work establishes film precursors using physical vapour deposition (PVD) techniques as a practical route to hydride formation, opening a pathway toward the controlled synthesis of promising ternary hydrides and the integration of micro-fabricated device geometries in diamond anvil cells.
