Crystal and electronic structures of BiS2-based compounds Sr0.5X0.5FBiS2 (X=rare earth) under pressure: Correlation with the change in the superconductivity from unconventional to conventional
Crystal and electronic structures of BiS2-based compounds Sr0.5X0.5FBiS2 (X=rare earth) under pressure: Correlation with the change in the superconductivity from unconventional to conventional
复制标题
BiS2基化合物Sr0.5X0.5FBiS2（X=稀土）在压力下的晶体和电子结构：与超导性从非常规到常规的变化的相关性
DOI：
10.1103/physrevb.106.205122
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发表时间：
2022
影响因子：
3.7
通讯作者：
Mizuguchi Yoshikazu
中科院分区：
文献类型：
--
作者：
Yamaoka Hitoshi;Yamashita Aichi;Nakahira Yuki;Ochi Masayuki;Kuroki Kazuhiko;Arima Hiroto;Matsubayashi Kazuyuki;Ishii Hirofumi;Hiraoka Nozomu;Mizuguchi Yoshikazu
被认为显示出在1 GPa附近的压力诱导的结构转变，其中随着超导转变温度的增加，超导性从低压相中的非常规变为高压相中的常规（）。我们阐明了高压相的单斜晶体结构（），这与（：硫族）系统的高压相相同。我们用高分辨X射线吸收光谱（XAS）系统地研究了Bi的电子结构，表明Bi的电荷态接近于Bi的电荷态。的XAS光谱的压力依赖性和indicate在结构转变压力，这对应于从类超导体的过渡到更多的金属状态周围的电子结构的大的变化。在高压阶段，观察到费米能级以上的Biand（）带空态的增加。密度泛函理论计算表明，费米能级的态密度在高压阶段没有显示出显著的变化，在那里观察到更高。
is considered to show a pressure-induced structural transition around 1 GPa where the superconductivity changes from unconventional in the low-pressure phase to conventional in the high-pressure phase with increasing the superconducting transition temperature (). We clarified the monoclinic crystal structure () in the high-pressure phase which is the same as the high-pressure phase of(: chalcogen) systems. We performed high-resolution x-ray absorption spectroscopy (XAS) to study the electronic structure ofsystematically, indicating the Bi charge state of nearly. The pressure dependence of the XAS spectra ofandindicate a large change in the electronic structure around the structural transition pressure, which corresponded to the transition from semiconductorlike to more metallic states. The increase of the empty states of Biand() bands above the Fermi level was observed in the high-pressure phase. Density functional theory calculations showed that the density of the states at the Fermi level did not show a significant change in the high-pressure phase, where higherwas observed.