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The 27th AIRAPT International Conference on High Pressure Science and Technology
Abstract

Oral


Superconducting Praseodymium Superhydrides

Authors:
Di Zhou (JILIN UNIVERSITY - State Key Laboratory of Superhard Materials) ; Dmitrii Semonok (SKOLTECH - Skolkovo Institute of Science and Technology) ; Hui Xie (JILIN UNIVERSITY - State Key Laboratory of Superhard Materials) ; Xiaoli Huang (JILIN UNIVERSITY - State Key Laboratory of Superhard Materials) ; Artem Oganov (SKOLTECH - Skolkovo Institute of Science and Technology, NORTHWESTERN POLYTECHNICAL UNIVERSITY - International Center for Materials Discovery ) ; Tian Cui (JILIN UNIVERSITY - State Key Laboratory of Superhard Materials)

Abstract:

Superhydrides are important prototype systems to investigate the metallization of hydrogen, room-temperature superconductivity and hydrogen storage compounds1, 2. By means of in situ laser-assisted decomposition of ammonia borane and reaction between the emitted hydrogen and Pr, we have synthesized two new Praseodymium superhydrides -PrH9 and P63/mmc-PrH9, two trihydrides: Fe3Al-type Fmm-PrH3 and P4/nmm-PrH3, as well as one rocksalt-type monohydride Fmm-PrH at pressure range 0 – 130 GPa. The found that P63/mmc-PrH9 is stable at 90-140 GPa and has the structure similar to previously studied CeH93. According to our calculations P63/mmc-PrH9 loses magnetic properties at 110 GPa and becomes superconductive with maximum Tc ~ 55 K and critical magnetic field μ0Hc (0) up to 15 T, while F3m-PrH9 is almost non-magnetic hydride. The cubic PrH9 has superconducting temperature Tc about 69 K and critical magnetic field μ0Hc (0) up to 17 T. Our results 6 highlight the intimate connection between hydrogen sublattice, electron density of state, magnetism and superconductivity in Pr-based superhydrides, which possess weak SC properties that fade along the La-Ce-Pr series3, 4, 5, while magnetic properties become more and more pronounced.

References

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2. F. Peng, Y. Sun, C. J. Pickard, R. J. Needs, Q. Wu, Y. Ma. Hydrogen Clathrate Structures in Rare Earth Hydrides at High Pressures: Possible Route to Room-Temperature Superconductivity. Phys. Rev. Lett. 119, 107001 (2017).

3. N. P. Salke et al. Synthesis of clathrate cerium superhydride CeH9 at 80 GPa with anomalously short H-H distance. arXiv:1805.02060, (2018).

4. M. Somayazulu et al. Evidence for Superconductivity above 260 K in Lanthanum Superhydride. Phys. Rev. Lett. 122, 027001 (2019).

  5. A. P. Drozdov et al. Superconductivity at 250 K in lanthanum hydride under high pressures arXiv:1812.01561, (2018).

    6. Di Zhou et al. Superconducting Praseodymium Superhydrides, https://arxiv.org/abs/1904.06643 (2019).