Chemically Tuning Stability and Superconductivity of P-H Compounds
Chemically Tuning Stability and Superconductivity of P-H Compounds
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化学调节 P-H 化合物的稳定性和超导性
DOI：
10.1021/acs.jpclett.9b03856
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Yanming Ma
中科院分区：
文献类型：
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作者：
Xue Li;Yu Xie;Ying Sun;Peihao Huang;Hanyu Liu;Changfeng Chen;Yanming Ma
实验证据表明，在压缩的固体膦中，超导性的临界温度Tc约为100 K，但理论研究迄今为止在任何二元P-H系统中都没有发现稳定的结构，这使得新超导体的特性尚未确定。在这里，我们提出了一个先进的结构搜索和第一性原理计算的结果，揭示了Li作为电子供体的作用，稳定了晶体结构，并在宽范围的化学计量和压力下产生强大的声子介导的超导电性的Li-P-H化合物。我们展示了一个三方LiP 2 H14相，在230 GPa下达到169 K的Tc，然后随着压力的升高而降低，这可以通过用Be或Na取代Li来弥补，这大大提高了Tc。这些发现突出了稳定晶体结构和增强不同类别的三元超导体的超导性的复杂而有效的化学调节，为设计和优化新的高Tchydride超导体开辟了新的途径。
Experimental evidence has revealed superconductivity with a critical temperature,Tc, around 100 K in compressed solid phosphine, but theoretical studies have hitherto found no stable structure in any binary P–H system, leaving the characterization of the new superconductor unsettled. Here we present the findings of an advanced structure search and first-principles calculations unveiling the effect of Li as an electron donor that stabilizes the crystal structure and produces robust phonon-mediated superconductivity in the resulting Li–P–H compounds in wide ranges of stoichiometry and pressure. We showcase a trigonal LiP2H14phase that reachesTcof 169 K at 230 GPa and then decreases with rising pressure, which can be remedied by substituting Li with Be or Na, which considerably enhancesTc. These findings highlight the intricate and effective chemical tuning of stabilizing the crystal structure and enhancing the superconductivity in a distinct class of ternary hydrides, opening new avenues for designing and optimizing new high-Tchydride superconductors.