Leading components and pressure-induced color changes in N-doped lutetium hydride

Abstract

Recent experimental study by Dias {\it et al.} claims to have discovered room-temperature superconductivity in lutetium-nitrogen-hydrogen system at 1 GPa [Nature 615, 244 (2023)], which sheds light on the long-held dream of ambient superconductivity. However, all follow-up experiments found no evidence of superconductivity. The compositions and the crystal structures of the lutetium-nitrogen-hydrogen system remain unknown. By employing the density functional theory based structure prediction algorithm, we suggest that in lutetium-nitrogen-hydrogen the major component is LuH${}_2$ (Fm$\bar{3}$m), together with minor LuN (Fm$\bar{3}$m). The blue LuH${}_2$ at ambient pressure will turn into purple and red color at higher pressures, possibly accompanied by the formation of vacancies at hydrogen-sites. In LuH${}_2$ and LuN, the density of states at the Fermi level is dominated by the Lu-5d orbitals, while those from hydrogen and nitrogen are very small, leading to the absence of superconductivity in these two compounds. Nitrogen-doping to LuH${}_2$ fails to enhance the superconductivity as well. In this work, we identify the leading components in N-doped lutetium hydride, explain its intriguing color changes under pressure, and elucidate why superconductivity is absent in the follow-up experiments.

References in corpus (12)

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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
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• First-principles study on the superconductivity of N-doped fcc-LuH3
• Lu-H-N phase diagram from first-principles calculations
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• Electronic and magnetic properties of Lu and LuH${}_2$

Cited by in corpus (16)

• Search for ambient superconductivity in the Lu-N-H system
• 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
• On parent structures of near-ambient nitrogen-doped lutetium hydride superconductor
• Ab initio study of the structural, vibrational and optical properties of potential parent structures of nitrogen-doped lutetium hydride
• Assessing the feasibility of near-ambient conditions superconductivity in the Lu-N-H system
• Electronic and magnetic properties of Lu and LuH${}_2$
• Transformation of hexagonal Lu to cubic LuH${}_{2+x}$ single-crystalline films
• Discovery of superconductivity in technetium-borides at moderate pressures
• Percolation-induced resistivity drop in cold-pressed LuH2
• Unveiling a Novel Metal-to-Metal Transition in LuH2: Critically Challenging Superconductivity Claims in Lutetium Hydrides
• Investigations of pressurized Lu-N-H materials by using the hybrid functional
• Crystal structures and high-temperature superconductivity in molybdenum-hydrogen binary system under high pressure
• Evidence of Molecular Hydrogen in the N-doped LuH3 System: a Possible Path to Superconductivity?
• Pressure-induced color change arising from transformation between intra- and inter-band transitions in LuH${}_{2\pm x}$N${}_y$
• Phonon-mediated superconductivity in transition-metal trioxides XO3 (X = Ru, Re, Os, Ir, Pt) under pressure