宁波大学崔田研究组取得一项新突破。他们的研究开发出了三元A15-(Lu，Y)₄H₂₃的高压合成及超导性。该项研究成果发表在2025年3月31日出版的《美国化学会杂志》上。

在这项工作中，课题组获得了由Lu和Y原子形成的三元氢化物，灵感来自于Lu - h系统稳定压力低且其4f电子被完全填充，以及Y - h系统的较高T_c。通过有效控制高压和高温条件，该课题组人员成功合成了Pm-3n (Lu，Y)₄H₂₃ （a15型）。合成的Pm-3n (Lu，Y)₄H₂₃在215 GPa下的T_c最高为112 K，是a15型超导体中最高的T_c记录。与二元材料Pm-3n Lu₄H₂₃相比，Pm-3n (Lu，Y)₄H₂₃的T_c值提高了60%，临界场μ₀H_c2(0)值提高了61%。有趣的是，由于Y原子的引入，Pm-3n (Lu，Y)₄H₂₃相对Pm-3n Lu₄H₂₃表现出最小的体积膨胀和H-H键距离的轻微增加。理论与实验相结合的分析表明，Lu原子被Y原子取代，通过修饰电子带和H-H键扩张引发的声子软化，增强了电子-声子耦合（EPC），共同驱动了Pm-3n (Lu，Y)₄H₂₃中T_c的显著增强。他们的工作为调整和提高氢化物的超导性能提供了重要的策略，并为三元氢化物的发展提供了宝贵的实践经验。

据介绍，三元氢化物是在二元氢化物中引入新元素形成的，是提高超导转变温度（T_c）或降低稳定压力的重要途径。

附：英文原文

Title: Synthesis and Superconductivity of Ternary A15-(Lu, Y)₄H₂₃ at High Pressures

Author: Kexin Zhang, Jingkun Yu, Yuchen Zhang, Jianning Guo, Yulong Wang, Chuang Jiang, Xiaoli Huang, Tian Cui

Issue&Volume: March 31, 2025

Abstract: Ternary hydrides, formed by introducing new elements into binary hydrides, are a crucial pathway for enhancing superconducting transition temperatures (Tc) or reducing the stable pressures. In this work, we have acquired the ternary hydride formed by Lu and Y atoms, inspired by the low stabilization pressure of the Lu–H system with its fully filled 4f electrons, as well as the higher Tc of the Y–H system. By effectively controlling the high-pressure and high-temperature conditions, we have successfully synthesized Pm-3n (Lu, Y)4H23 (A15-type). The synthesized Pm-3n (Lu, Y)4H23 reveals the highest Tc of 112 K at 215 GPa, which is the record Tc among A15-type superconductors. Compared to the binary Pm-3n Lu4H23, the Pm-3n (Lu, Y)4H23 exhibits a 60% increase in Tc and a 61% enhancement in the upper critical field μ0Hc2(0). Interestingly, Pm-3n (Lu, Y)4H23 displays minimal volume expansion and a slight increase in the H–H bond distance relative to Pm-3n Lu4H23 due to the introduction of Y atoms. Combined theoretical and experimental analyses indicate that the substitution of Lu atoms with Y atoms enhances electron–phonon coupling (EPC) through modified electronic bands and phonon softening caused by the expansion of H–H bonds, collectively driving the significant enhancement of Tc in Pm-3n (Lu, Y)4H23. Our work demonstrates a crucial strategy for adjusting and enhancing the superconducting performance of hydrides and offers valuable practical experience for developing ternary hydrides.

DOI: 10.1021/jacs.4c16805

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c16805