Zhou Di, Semenok Dmitrii V, Duan Defang, Xie Hui, Chen Wuhao, Huang Xiaoli, Li Xin, Liu Bingbing, Oganov Artem R, Cui Tian
State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
Skolkovo Institute of Science and Technology, Skolkovo Innovation Center 143026, 3 Nobel Street, Moscow, Russia.
Sci Adv. 2020 Feb 28;6(9):eaax6849. doi: 10.1126/sciadv.aax6849. eCollection 2020 Feb.
Superhydrides have complex hydrogenic sublattices and are important prototypes for studying metallic hydrogen and high-temperature superconductors. Previous results for LaH suggest that the Pr-H system may be especially worth studying because of the magnetism and valence-band -electrons in the element Pr. Here, we successfully synthesized praseodymium superhydrides (PrH) in laser-heated diamond anvil cells. Synchrotron x-ray diffraction analysis demonstrated the presence of previously predicted 3-PrH and unexpected 6/-PrH phases. Experimental studies of electrical resistance in the PrH sample showed the emergence of a possible superconducting transition ( ) below 9 K and dependent on the applied magnetic field. Theoretical calculations indicate that magnetic order and likely superconductivity coexist in a narrow range of pressures in the PrH sample, which may contribute to its low superconducting temperature. Our results highlight the intimate connections between hydrogenic sublattices, density of states, magnetism, and superconductivity in Pr-based superhydrides.
超氢化物具有复杂的氢亚晶格，是研究金属氢和高温超导体的重要原型。先前关于LaH的研究结果表明，由于元素Pr中的磁性和价带电子，Pr-H体系可能特别值得研究。在此，我们在激光加热金刚石对顶砧中成功合成了镨超氢化物（PrH）。同步辐射X射线衍射分析表明存在先前预测的3-PrH相和意想不到的6/-PrH相。对PrH样品电阻的实验研究表明，在9K以下出现了可能的超导转变（ ），且该转变依赖于外加磁场。理论计算表明，PrH样品在窄压力范围内磁有序和可能的超导性共存，这可能是其超导温度较低的原因。我们的结果突出了镨基超氢化物中氢亚晶格、态密度、磁性和超导性之间的密切联系。
