Efficient route to achieve superconductivity improvement via substitutional La-Ce alloy superhydride at high pressure

Fuente: arXiv
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Auteurs principaux: Bi, Jingkai, Nakamoto, Yuki, Shimizu, Katsuya, Zhou, Mi, Wang, Hongbo, Liu, Guangtao, Ma, Yanming
Format: Preprint
Publié: 2022
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author Bi, Jingkai
Nakamoto, Yuki
Shimizu, Katsuya
Zhou, Mi
Wang, Hongbo
Liu, Guangtao
Ma, Yanming
author_facet Bi, Jingkai
Nakamoto, Yuki
Shimizu, Katsuya
Zhou, Mi
Wang, Hongbo
Liu, Guangtao
Ma, Yanming
contents The discovery of clathrate superhydrides has approached the long-standing dream of room-temperature superconductivity and thus inspired their prosperous research under high pressure. However, how to experimentally optimize these compelling superhydrides is still a formidable challenge. Here, we find that half of the Ce atoms in the recently discovered hexagonal close packed (hcp) CeH9 structure can be randomly replaced by adjacent La, resulting in the formation of LaH9 unit that is impossible in a binary system. Our experiments show that hcp (La, Ce)H9 can be synthesized at ~110 GPa and possesses a maximum Tc of 178 K at higher pressure, which is evidenced by in-situ X-ray diffraction and electronic transport measurement where a sharp drop of resistivity to zero and a characteristic decrease of Tc under a magnetic field up to 9 T. More importantly, the Tc of (La, Ce)H9 is significantly increased by ~50-80 K compared to CeH9, showing the hitherto highest Tc at megabar pressure. Our experimental results not only verify the feasibility of improving the superconductivity of hydrides by introducing other suitable metals, but also provide important inspiration for finding high-Tc superconductors in various multinary superhydrides.
format Preprint
id arxiv_https___arxiv_org_abs_2204_04623
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Efficient route to achieve superconductivity improvement via substitutional La-Ce alloy superhydride at high pressure
Bi, Jingkai
Nakamoto, Yuki
Shimizu, Katsuya
Zhou, Mi
Wang, Hongbo
Liu, Guangtao
Ma, Yanming
Superconductivity
Materials Science
The discovery of clathrate superhydrides has approached the long-standing dream of room-temperature superconductivity and thus inspired their prosperous research under high pressure. However, how to experimentally optimize these compelling superhydrides is still a formidable challenge. Here, we find that half of the Ce atoms in the recently discovered hexagonal close packed (hcp) CeH9 structure can be randomly replaced by adjacent La, resulting in the formation of LaH9 unit that is impossible in a binary system. Our experiments show that hcp (La, Ce)H9 can be synthesized at ~110 GPa and possesses a maximum Tc of 178 K at higher pressure, which is evidenced by in-situ X-ray diffraction and electronic transport measurement where a sharp drop of resistivity to zero and a characteristic decrease of Tc under a magnetic field up to 9 T. More importantly, the Tc of (La, Ce)H9 is significantly increased by ~50-80 K compared to CeH9, showing the hitherto highest Tc at megabar pressure. Our experimental results not only verify the feasibility of improving the superconductivity of hydrides by introducing other suitable metals, but also provide important inspiration for finding high-Tc superconductors in various multinary superhydrides.
title Efficient route to achieve superconductivity improvement via substitutional La-Ce alloy superhydride at high pressure
topic Superconductivity
Materials Science
url https://arxiv.org/abs/2204.04623