论文标题
高压合成的七个灯笼氢化物具有显着变化的氢含量
High-Pressure Synthesis of Seven Lanthanum Hydrides with a Significant Variability of Hydrogen Content
论文作者
论文摘要
在近气温和高压力下LAH10中的超导性报告后，灯笼 - 氢系统引起了极大的关注。在这里，我们介绍了该系统上的单晶X射线衍射研究的结果，并得到密度功能理论计算的支持，该计算揭示了在50至180 GPA范围内合成的灯笼氢化物的意外化学和结构多样性。产生了七个灯笼氢化物，LaH3，LAH〜4，LAH4+δ，LA4H23，LAH6+δ，LaH9+δ和LAH10+δ，以及在确定其结构中的Lanthanum的原子坐标。这里揭示的稀土元素氢化物的规律性提供了指导搜索其他合成氢化物和候选高温超导体的线索。灯笼氢化物中的氢含量变异性和样品的相位异质性强调了与评估潜在的超导相关的挑战以及高压氢化物中电子过渡的性质。
The lanthanum-hydrogen system has attracted significant attention following the report of superconductivity in LaH10 at near-ambient temperatures and high pressures. Here, we present the results of our single-crystal X-ray diffraction studies on this system, supported by density functional theory calculations, which reveal an unexpected chemical and structural diversity of lanthanum hydrides synthesized in the range of 50 to 180 GPa. Seven lanthanum hydrides were produced, LaH3, LaH~4, LaH4+δ, La4H23, LaH6+δ, LaH9+δ, and LaH10+δ, and the atomic coordinates of lanthanum in their structures determined. The regularities in rare-earth element hydrides unveiled here provide clues to guide the search for other synthesizable hydrides and candidate high-temperature superconductors. The hydrogen content variability in lanthanum hydrides and the samples' phase heterogeneity underline the challenges related to assessing potentially superconducting phase(s) and the nature of electronic transitions in high-pressure hydrides.
