论文标题
LA $ _ {0.5} $ CE $ _ {0.5} $ H $ _ {10} $的超导阶段的合成
Synthesis of Superconducting Phase of La$_{0.5}$Ce$_{0.5}$H$_{10}$ at High Pressures
论文作者
论文摘要
杂质氢化物\ emph {fm} \ = {3} \ emph {m} -lah $ _ {10} $已被证明是近年来GPA压缩时临界温度$ T_C $高于250 k的最非凡的超导体。一般的希望是降低稳定压力，并保持LAH $ _ {10} $的特定阶段的高$ T_C $值。但是，强结构不稳定性扭曲\ emph {fm} \ = {3} \ emph {m}结构，并导致低压下的$ t_c $迅速减少。在这里，我们研究了\ emph {fm} \ = {3} \ emph {m} -lah $ _ {10} $的相位稳定性和超导行为，并通过从两个实验和计算中通过CE部分代替LA，并通过对LA的一部分替换化学预压。为了明确表征合成的氢化物，我们选择具有1：1的化学计量成分组成的灯笼 - 毛细管合金。 X射线衍射和拉曼散射测量结果揭示了\ emph {fm} \ = {3} \ emph {m} -la $ _ {0.5} $ _ {0.5} $ _ {0.5} $ _ {0.5} $ _ {0.5} $ h $ _ {10} $在140-160 gpa的压力范围内。 $ T_C $的超导性为175美元$ \ pm $ \ pm $ 2 k $ 2 k在155 GPA的情况下，通过观察零电阻状态，并得到理论计算的支持。这些发现为将来的各种富含氢的氢化物提供了适用性。
Clathrate hydride \emph{Fm}\={3}\emph{m}-LaH$_{10}$ has been proven as the most extraordinary superconductor with the critical temperature $T_c$ above 250 K upon compression of hundreds of GPa in recent years. A general hope is to reduce the stabilization pressure and maintain the high $T_c$ value of the specific phase in LaH$_{10}$. However, strong structural instability distorts \emph{Fm}\={3}\emph{m} structure and leads to a rapid decrease of $T_c$ at low pressures. Here, we investigate the phase stability and superconducting behaviors of \emph{Fm}\={3}\emph{m}-LaH$_{10}$ with enhanced chemical pre-compression through partly replacing La by Ce atoms from both experiments and calculations. For explicitly characterizing the synthesized hydride, we choose lanthanum-cerium alloy with stoichiometry composition of 1:1. X-ray diffraction and Raman scattering measurements reveal the stabilization of \emph{Fm}\={3}\emph{m}-La$_{0.5}$Ce$_{0.5}$H$_{10}$ in the pressure range of 140-160 GPa. Superconductivity with $T_c$ of 175$\pm$2 K at 155 GPa is confirmed with the observation of the zero-resistivity state and supported by the theoretical calculations. These findings provide applicability in the future explorations for a large variety of hydrogen-rich hydrides.
