Figure 8

Comparison of crystal structure of typical Bi-based layered compounds with different thickness of superconducting layer. (a) Schematic image of the crystal structure of Bi₃O₂S₂Cl, which was recently discovered by Ruan et al.³⁴. In this material, the conducting layer can be regarded as the one-layer-type BiS₂Cl. (b) Schematic image of the crystal structure of the typical BiS₂-based superconductor RE(O,F)BiS₂. In the series, the conducting layer can be regarded as the two-layer-type Bi₂S₄ bilayer. (c) Schematic image of the crystal structure of La₂O₂Bi₃AgS₆-type (La₂O₂M₄S₆-type) materials whose conducting layer can be regarded as the four-layer-type M₄S₆ layer.