论文标题
在高压下耐氦的超导体
Helium-bearing superconductor at high pressure
论文作者
论文摘要
在环境条件下，氦（HE）是最惰性的贵重气体。它采用了六角形的封闭结构（p63/mmc），并保持在最高32 tpa的绝缘阶段。相反，锂（Li）是零压力下最具反应性的金属之一，而其立方高压相（FD-3M）是高于475 GPA的弱金属电气。令人惊讶的是，通过将FD-3M LI与p63/mmc He混合在700 GPA以上的FD-3M LI来形成LI5HE2（R-3M）的稳定化合物。氦的存在促进了从FD-3M LI到PM-3M LI的晶格转化，并将三维分布的间质电子调整为零和二维阴离子电子电子的混合物。因此，这显着增加了在费米水平上的金属化程度，因此，导电阴离子电子与LI为主导的振动的偶联是形成超导电气LI5HE2与转变温度高达26 K的关键因素，并在26 K中，动态稳定至210 GPA的压力。
Helium (He) is the most inert noble gas at ambient conditions. It adopts a hexagonal close packed structure (P63/mmc) and remains in the insulating phase up to 32 TPa. In contrast, lithium (Li) is one of the most reactive metals at zero pressure, while its cubic high-pressure phase (Fd-3m) is a weak metallic electride above 475 GPa. Strikingly, a stable compound of Li5He2 (R-3m) was formed by mixing Fd-3m Li with P63/mmc He above 700 GPa. The presence of helium promotes the lattice transformation from Fd-3m Li to Pm-3m Li, and tuns the three-dimensional distributed interstitial electrons into the mixture of zero- and two-dimensional anionic electrons. This significantly increases the degree of metallization at the Fermi level, consequently, the coupling of conductive anionic electrons with the Li-dominated vibrations is the key factor to the formation of superconducting electride Li5He2 with a transition temperature up to 26 K, dynamically stable to pressures down to 210 GPa.
