The near room-temperature upsurge of electrical resistivity in Lu-H-N is not superconductivity, but a metal-to-poor-conductor transition

Abstract

Since the discovery of superconductivity in mercury at 4 K in 1911, searching for materials with superconductivity at higher temperatures towards practical conditions has been a primary enduring goal. The recent report of room-temperature superconductivity at near-ambient pressure in nitrogen-doped lutetium hydride (Lu-H-N) by Dasenbrock-Gammon et al. (Hereafter referred as D-G) seems a great step approaching the ultimate goal. Specifically, they claimed evidence of superconductivity on Lu-H-N with a maximum Tc of 294 K at 1 GPa. However, the failure to observe the drastic temperature-dependent resistance change above 200 K in high-pressure synthesized Lu-H-N compounds, a prerequisite for superconductivity, by researchers worldwide in all independent follow-up studies casts a heavy shadow on the authenticity of the claims. The sober questions are: what is the sample that produces the sharp resistance jump near room temperature? What are the reasons for the non-reproducibility of others who follow the D-G method of synthesis and the inscrutable low success rate (35%) in synthesizing the right sample even for the authors in Ref. 1? What causes the observed sharp resistance jump? Here, with a well-controlled experiment protocol, we repeatedly reproduced the near room-temperature sudden change of electrical resistance in the Lu-H-N sample, and we could quantitatively compare its behavior with the initial pure Lu in a normal metallic state. These results enable us to scrutinize the origin for the near-room temperature sharp resistance change, which is attributed to a metal-to-poor-conductor transition rather than superconductivity.

6 pages, 1 figure

References in corpus (13)

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Cited by in corpus (16)

• Search for ambient superconductivity in the Lu-N-H system
• Structure, Stability and Superconductivity of N-doped Lutetium Hydrides at kbar Pressures
• 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${}_2$
• Enormous variation in homogeneity and other anomalous features of room temperature superconductor samples: a Comment on Nature 615, 244 (2023)
• Transformation of hexagonal Lu to cubic LuH${}_{2+x}$ single-crystalline films
• Percolation-induced resistivity drop in cold-pressed LuH2
• Unveiling a Novel Metal-to-Metal Transition in LuH2: Critically Challenging Superconductivity Claims in Lutetium Hydrides
• Crystal structures and high-temperature superconductivity in molybdenum-hydrogen binary system under high pressure
• 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?
• Phonon-mediated superconductivity in transition-metal trioxides XO3 (X = Ru, Re, Os, Ir, Pt) under pressure