Synthesis of superconducting phase of La0.5Ce0.5H10at high pressures

Ge Huang; Di Peng; Tao Luo; Liu-Cheng Chen; Philip Dalladay-Simpson; Zi-Yu Cao; Federico A Gorelli; Guo-Hua Zhong; Hai-Qing Lin; Xiao-Jia Chen

doi:10.1088/1361-648X/ad0915

Synthesis of superconducting phase of La_0.5Ce_0.5H₁₀at high pressures

J Phys Condens Matter. 2023 Nov 10;36(7). doi: 10.1088/1361-648X/ad0915.

Authors

Ge Huang¹, Di Peng^{2

3}, Tao Luo⁴, Liu-Cheng Chen^{1

4}, Philip Dalladay-Simpson¹, Zi-Yu Cao^{1

5}, Federico A Gorelli^{1

6}, Guo-Hua Zhong^{7

8}, Hai-Qing Lin⁹, Xiao-Jia Chen¹⁰

Affiliations

¹ Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China.
² Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
³ University of Science and Technology of China, Hefei 230026, People's Republic of China.
⁴ School of Science, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China.
⁵ Center for Quantum Materials and Superconductivity (CQMS) and Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
⁶ National Institute of Optics (INO-CNR) and European Laboratory for Non-Linear Spectroscopy (LENS), Via N. Carrara 1, 50019 Sesto Fiorentino (Florence), Italy.
⁷ Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, Shenzhen, People's Republic of China.
⁸ University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
⁹ School of Physics, Zhejiang University, Hangzhou 310058, People's Republic of China.
¹⁰ Department of Physics and Texas Center for Superconductivity, University of Houston, Houston TX 77204, United States of America.

PMID: 37918102
DOI: 10.1088/1361-648X/ad0915

Abstract

Clathrate hydrideFm3-m-LaH₁₀has been proven as the most extraordinary superconductor with the critical temperatureT_cabove 250 K upon compression of hundreds of GPa in recent years. A general hope is to reduce the stabilization pressure and maintain the highT_cvalue of the specific phase in LaH₁₀. However, strong structural instability distortsFm3-mstructure and leads to a rapid decrease ofT_cat low pressures. Here, we investigate the phase stability and superconducting behaviors ofFm3-m-LaH₁₀with enhanced chemical pre-compression through partly replacing La by Ce atoms from both experiments and calculations. For explicitly characterizing the synthesized hydride, we choose lanthanum-cerium alloy with stoichiometry composition of 1:1. X-ray diffraction and Raman scattering measurements reveal the stabilization ofFm3-m-La_0.5Ce_0.5H₁₀in the pressure range of 140-160 GPa. Superconductivity withT_cof 175 ± 2 K at 155 GPa is confirmed with the observation of the zero-resistivity state and supported by the theoretical calculations. These findings provide applicability in the future explorations for a large variety of hydrogen-rich hydrides.

Keywords: La0.5Ce0.5H10; LaH10; electron–phonon coupling; hydride; superconductivity.