On parent structures of near-ambient nitrogen-doped lutetium hydride superconductor

Abstract

Recently, near-ambient superconductivity has been experimentally evidenced in a nitrogen-doped lutetium hydride by Dasenbrock-Gammon \emph{et al.} [Nature 615, 244 (2023)], which yields a remarkable maximum $T_c$ of 294 K at just 10 kbar. However, due to the difficulty of x-ray diffraction (XRD) in identifying light elements such as hydrogen and nitrogen, the crystal structure of the superconductor remains elusive, in particular for the actual stoichiometry of hydrogen and nitrogen and their atomistic positions. This holds even for its parent structure. Here, we set out to address this issue by performing a thorough density functional theory study on the structural, electronic, dynamical, and optical properties of lutetium hydrides. Through thermal and lattice dynamic analysis as well as XRD and superconductor color comparisons, we unambiguously clarified that the parent structures are a mixture of dominant LuH${}_2$ phase of the CaF${}_2$-type (instead of originally proposed LuH${}_3$ structure of $Fm\bar{3}m$ space group) and minor LuH phase of the NaCl-type.

4 pages, 3 figures

References in corpus (13)

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• Absence of near-ambient superconductivity in LuH${}_{2\pm \text{x}}$N${}_y$
• Superconductivity above 70 K observed in lutetium polyhydrides
• Phase Diagram and Superconductivity of Calcium Borohyrides at Extreme Pressures
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• First-principles study on the superconductivity of N-doped fcc-LuH3
• Lu-H-N phase diagram from first-principles calculations
• Effect of nitrogen doping and pressure on the stability of LuH${}_3$
• Pressure induced color change and evolution of metallic behavior in nitrogen-doped lutetium hydride
• Metal Borohydrides as high-$T_c$ ambient pressure superconductors
• Leading components and pressure-induced color changes in N-doped lutetium hydride
• Structural Diversity and Superconductivity in S-P-H Ternary Hydrides Under Pressure

Cited by in corpus (16)

• Search for ambient superconductivity in the Lu-N-H system
• First-principles study on the superconductivity of N-doped fcc-LuH3
• Structure, Stability and Superconductivity of N-doped Lutetium Hydrides at kbar Pressures
• The near room-temperature upsurge of electrical resistivity in Lu-H-N is not superconductivity, but a metal-to-poor-conductor transition
• Observation of non-superconducting phase changes in LuH${}_{2\pm \text{x}}$N${}_y$
• Temperature and quantum anharmonic lattice effects on stability and superconductivity in lutetium trihydride
• Leading components and pressure-induced color changes in N-doped lutetium hydride
• Assessing the feasibility of near-ambient conditions superconductivity in the Lu-N-H system
• Microscopic theory of colour in lutetium hydride
• Electronic and magnetic properties of Lu and LuH${}_2$
• Novel Electronic Structure of Nitrogen-Doped Lutetium Hydrides
• Anatomy of the band structure of the newest apparent near-ambient superconductor LuH${}_{3-x}$N${}_x$
• Investigations of pressurized Lu-N-H materials by using the hybrid functional
• Pressure-induced color change arising from transformation between intra- and inter-band transitions in LuH${}_{2\pm x}$N${}_y$
• Evidence of Molecular Hydrogen in the N-doped LuH3 System: a Possible Path to Superconductivity?
• Ternary Phase Diagram of Nitrogen Doped Lutetium Hydrides