Origin of the near-room temperature resistance transition in lutetium with H2/N2 gas mixture under high pressure

Di Peng; Qiaoshi Zeng; Fujun Lan; Zhenfang Xing; Zhidan Zeng; Xiaoxing Ke; Yang Ding; Ho-Kwang Mao

doi:10.1093/nsr/nwad337

Origin of the near-room temperature resistance transition in lutetium with H₂/N₂ gas mixture under high pressure

Natl Sci Rev. 2023 Dec 30;11(7):nwad337. doi: 10.1093/nsr/nwad337. eCollection 2024 Jul.

Authors

Di Peng^{1

2

3}, Qiaoshi Zeng^{3

4}, Fujun Lan³, Zhenfang Xing^{3

5}, Zhidan Zeng³, Xiaoxing Ke⁶, Yang Ding³, Ho-Kwang Mao^{3

4}

Affiliations

¹ Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences, Hefei 230031, China.
² Science Island Branch, Graduate School of University of Science and Technology of China, Hefei 230026, China.
³ Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.
⁴ Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments (MFree), Shanghai Advanced Research in Physical Sciences (SHARPS), Shanghai 201203, China.
⁵ State Key Laboratory of Superhard Materials, Institute of Physics, Jilin University, Changchun 130012, China.
⁶ College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, China.

Abstract

The recent report of room-temperature superconductivity at near-ambient pressure in nitrogen-doped lutetium hydride (Lu-H-N) by Dasenbrock-Gammon et al. [Nature 615, 244-250 (2023)] has attracted tremendous attention due to its anticipated great impact on technology. However, the results could not be independently reproduced by other groups worldwide in follow-up studies, which elicited intense controversy. Here, we develop a reliable experimental protocol to minimize the extensively concerned extrinsic influences on the sample by starting the reaction from pure lutetium loaded with an H₂/N₂ gas mixture in a diamond anvil cell under different pressures and temperatures and simultaneously monitoring the entire chemical reaction process using in situ four-probe resistance measurements. Therefore, we could repeatedly reproduce the near-room temperature upsurge of electrical resistance at a relatively early stage of the chemical reaction. However, the mechanism is suggested to be a metal-to-semiconductor/insulator transition associated with the structural modulation in the non-stoichiometric Lu-H-N, rather than superconductivity.

Keywords: high pressure; lutetium hydride; metal-to-semiconductor/insulator transition; resistance transition; superconductivity.