Anomalous Charge State Evolution and Its Control of Superconductivity in M3Al2C (M = Mo, W)
Anomalous Charge State Evolution and Its Control of Superconductivity in M3Al2C (M = Mo, W)
复制标题
M3Al2C (M = Mo, W) 中的反常电荷态演化及其对超导性的控制
DOI：
10.1016/j.isci.2020.101196
复制
发表时间：
2020
期刊：
影响因子：
5.8
通讯作者：
Hosono Hideo
中科院分区：
文献类型：
--
作者：
Ying Tianping;Muraba Yoshinori;Iimura Soshi;Yu Tongxu;Cheng Peihong;Kamiya Toshio;Lu Yangfan;Li Jiang;Qi Yanpeng;Hosono Hideo
元素的电荷状态直接或间接地决定了晶格中电子和声子的行为。本文报道了在M_3Al_2C（M= Mo，W）超导体系中发现的一种反常电荷态演化，其中电子掺杂可以通过“氧化”来实现。“具体来说，随着电子供体（Al）从结构中的连续去除，我们发现了带负电荷的过渡金属中的电子掺杂效应。在一定的阈值之上，过渡金属的电荷状态经历从负到正的突然逆转，这导致随后的结构崩溃。同时，以前的强大的超导转变温度（Tcs）可以灵活地调制。详细的分析揭示了超导电性的起源以及电荷态与电子-声子耦合常数之间的密切关系。M_3Al_2C中的特殊电荷态对它的结构和超导电性都起着重要的作用。
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 superconductingM3Al2C (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 inM3Al2C plays an important role in both its structure and superconductivity.