Transformation of Hexagonal Lu to Cubic LuH2+x Single-Crystalline Films
Transformation of Hexagonal Lu to Cubic LuH2+x Single-Crystalline Films
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DOI：
10.1088/0256-307x/40/8/087401
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发表时间：
2023-07-01
影响因子：
3.5
通讯作者：
Cao, Yanwei
中科院分区：
文献类型：
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作者：
Li, Peiyi;Bi, Jiachang;Cao, Yanwei
近年来，随着掺氮氢化镥（Lu-H-N）体系室温下近环境超导性的报道，对立方Lu-H化合物的认识引起了世界范围内的广泛关注。通常，与具有不可忽略的杂质的多晶体相比，具有高纯度的材料的单晶形式可以提供展示其隐藏特性的机会。然而，迄今为止，单晶立方Lu-H化合物的实验合成还未见报道。在这里，我们开发了一种简单的方法来合成高纯度的LuH 2 +x单晶薄膜的后退火的Lu单晶薄膜（纯度为99.99%）在H-2气氛。薄膜的晶体结构和电子结构，其特征在于通过X射线衍射，拉曼光谱，和电输运。有趣的是，Lu膜是银白色和金属，而它们的转化LuH 2 +x膜变成紫红色和绝缘，表明Lu-H化合物的未报道的电子态的可能形成。我们的工作为合成和探索更多的单晶Lu-H化合物提供了一条新的途径。
With the recent report of near ambient superconductivity at room temperature in the N-doped lutetium hydride (Lu-H-N) system, the understanding of cubic Lu-H compounds has attracted worldwide attention. Generally, compared to polycrystals with non-negligible impurities, the single-crystalline form of materials with high purity can provide an opportunity to show their hidden properties. However, the experimental synthesis of single-crystalline cubic Lu-H compounds has not been reported so far. Here, we develop an easy way to synthesize highly pure LuH2+x single-crystalline films by the post-annealing of Lu single-crystalline films (purity of 99.99%) in H-2 atmosphere. The crystal and electronic structures of films were characterized by x-ray diffraction, Raman spectroscopy, and electrical transport. Interestingly, Lu films are silver-white and metallic, whereas their transformed LuH2+x films become purple-red and insulating, indicating the possible formation of an unreported electronic state of Lu-H compounds. Our work provides a novel route to synthesize and explore more single-crystalline Lu-H compounds.