Pressure-stabilized superconducting electride Li5C

作     者：Qinfang Wang Wenwen Cui Kun Gao Ju Chen Tingting Gu Meixu Liu Jian Hao Jingming Shi Yinwei Li 

作者机构：Laboratory of Quantum Functional Materials Design and Application School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou 221116 China Department of Physics School of Physics and Electronic Science East China Normal University Shanghai 200241 China Shandong Key Laboratory of Optical Communication Science and Technology School of Physical Science & Information Technology of Liaocheng University Liaocheng 252059 China 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2022年第106卷第5期

页      面：054519-054519页

核心收录：

基　　金：333 High-level Talents Project of Jiangsu Province Postgraduate Research & Practice Innovation Program of Jiangsu Province, (2021XKT1236) Six Talent Peaks Project National Natural Science Foundation of China, NSFC, (11722433, 11804128, 11804129, 12074154, 12174160) National Natural Science Foundation of China, NSFC Xuzhou Science and Technology Program, (KC19010) Xuzhou Science and Technology Program 

主　　题：First-principles calculations Phase transitions Pressure effects Superconductivity 

摘      要：The search for electrides has recently attracted great interest owing to their unique physical properties, such as superconductivity. Li5C has been proposed as a candidate electride with a high superconducting critical temperature Tc of 48 K originating mainly from the localized electrons. Here, a combination of structure searches and first-principles calculations has been performed to acquire the phase diagrams of a Li-C system at high pressure. The structure searches unraveled four successive structures under pressure for Li5C that are energetically more stable than the previously proposed superconducting one. The dimension of the localized electrons in Li5C decreases under compression due to the reduced interstitial voids. Electron-phonon calculations demonstrated that the four Li5C phases are superconductors with a maximum Tc of 5.7 K, excluding its possibility of high superconductivity. Analysis showed that the host hybridized electrons, instead of interstitial electrons, contribute mainly to the superconductivity in Li5C.