Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6

TL;DR

This study reports the synthesis, detailed crystal structure analysis, and physical property characterization of a new layered oxychalcogenide, La2O2Bi3AgS6, revealing its metallic electronic behavior and structural similarities to related compounds.

Contribution

The paper introduces a novel layered oxychalcogenide compound with detailed structural refinement and physical property insights, expanding the family of layered chalcogenide materials.

Findings

Crystal structure refined with P4/nmm space group

Electronic states are more metallic than related compounds

Insertion of rock-salt-type chalcogenide is a promising design strategy

Abstract

We have synthesized a new layered oxychalcogenide La2O2Bi3AgS6. From synchrotron X-ray diffraction and Rietveld refinement, the crystal structure of La2O2Bi3AgS6 was refined using a model of the P4/nmm space group with a = 4.0644(1) {\AA} and c = 19.412(1) {\AA}, which is similar to the related compound LaOBiPbS3, while the interlayer bonds (M2-S1 bonds) are apparently shorter in La2O2Bi3AgS6. The tunneling electron microscopy (TEM) image confirmed the lattice constant derived from Rietveld refinement (c ~ 20 {\AA}). The electrical resistivity and Seebeck coefficient suggested that the electronic states of La2O2Bi3AgS6 are more metallic than those of LaOBiS2 and LaOBiPbS3. The insertion of a rock-salt-type chalcogenide into the van der Waals gap of BiS2-based layered compounds, such as LaOBiS2, will be a useful strategy for designing new layered functional materials in the layered chalcogenide family.