Superconductivity in layered oxychalcogenide La₂O₂Bi₃AgS₆

We report the superconductivity in layered oxychalcogenide La₂O₂Bi₃AgS₆ compound. The La₂O₂Bi₃AgS₆ compound has been reported recently by our group, which has a tetragonal structure with the space group P4/nmm. The crystal structure of La₂O₂Bi₃AgS₆ can be regarded as alternate stacks of LaOBiS₂-type layer and rock-salt-type (Bi,Ag)S layer. We measured low-temperature electrical resistivity and observed superconductivity at 0.5 K. The observation of superconductivity in the La₂O₂Bi₃AgS₆ should provide us with the successful strategy for developing new superconducting phases by the insertion of a rock-salt-type chalcogenide layer into the van der Waals gap of BiS₂-based layered compound like LaOBiS₂. (author)