Evaluation of Bi defect concentration in LnO1-xFxBiCh 2 by scanning tunneling microscopy

29th International Symposium on Superconductivity

Demura, S.^1 ; Ishida, N.^1 ; Fujisawa, Y.^1 ; Sakata, H.^1

Department of Physics, Tokyo University of Science, Shinjyuku-ku, Tokyo

162-8601, Japan^1

关键词: Defect concentrations;    Electron carrier;    Real-space;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/871/1/012006/pdf
DOI  :  10.1088/1742-6596/871/1/012006

来源: IOP

【 摘 要 】

We examined a concentration of Bi defects in layered BiCh2based superconductors LnO1-xFxBiCh2(Ln = La, Ce, Nd Ch = S, Se). These materials show superconductivity by electron carrier doping into BiCh2layer. Since Bi defects affect the carrier concentration directly, an examination of the concentration is important to evaluate an actual carrier concentration. In this paper, the concentration of Bi defects on the BiCh2layers in BiCh2based superconductors was evaluated by scanning tunneling microscopy measurements in real space. We found the samples with BiSe2layers have less Bi defects than those with BiS2layers. Furthermore, the concentration of Bi defects was found to be almost constant regardless of F concentration and Ln ion.