Anomalous Charge State Evolution and Its Control of Superconductivity in M3Al2C (M = Mo, W)

iScience

卷:23

Peihong Cheng¹  Soshi Iimura²  Yangfan Lu²  Yoshinori Muraba²  Jiang Li²  Yanpeng Qi²  Tianping Ying²  Hideo Hosono³  Toshio Kamiya³  Tongxu Yu⁴ 

[1] Laboratory of Advanced Materials, Fudan University, Shanghai 200438, China;

[2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan;

[3] School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China;

[4] State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200438, China;

关键词: Phase Transitions;    Superconductivity;    Condensed Matter Properties;    Structural Property of Condensed Matter;   

DOI  :  

来源: DOAJ

【 摘 要 】

Summary: The charge states of elements dictate the behavior of electrons and phonons in a lattice, either directly or indirectly. Here, we report the discovery of an anomalous charge state evolution in the superconducting M3Al2C (M = Mo, W) system, where electron doping can be achieved through “oxidation.” Specifically, with the continuous removal of electron donor (Al) from the structure, we found an electron doping effect in the negatively charged transition metals. Over a certain threshold, the charge state of transition metals goes through a sudden reversion from negative to positive, which leads to a subsequent structure collapse. Concomitantly, the previous robust superconducting transition temperatures (Tcs) can be flexibly modulated. Detailed analysis reveals the origin of the superconductivity and the intimate relationship between the charge state and the electron-phonon coupling constant. The peculiar charge state in M3Al2C plays an important role in both its structure and superconductivity.

【 授权许可】

Unknown