Crystal structures of LaO1−xFxBiS2 (x~0.23, 0.46): Effect of F doping on distortion of Bi–S plane

• Crystal structure of LaO1−xFxBiS2 was determined by single-crystal XRD.
• Doping amount of F changes the distortion of the Bi–S plane.
• Nearly flat Bi–S planes were found in superconductive LaO1−xFxBiS2 (x~0.46).
• LaO1−xFxBiS2 with higher F contents was thermodynamically more unstable.
• Bonding, superconductivities, and synthetic routes of LaO1−xFxBiS2 were discussed.

The crystal structures of superconducting LaO1−xFxBiS2 (x~0.23, 0.46) were determined by single-crystal X-ray diffraction analysis. Their space group was P4/nmm. Distortion of the Bi–S plane changed when the F content was increased from 0.23 to 0.46, and a nearly flat Bi–S plane was formed at x~0.46. Computational calculations supported this effect of F doping on distortion of Bi–S plane. LaO1−xFxBiS2 with higher F contents were computationally predicted to be thermodynamically more unstable under ambient pressure. We discussed the bonding, conductivities, and synthetic routes of LaO1−xFxBiS2.

Distortion of the Bi–S plane in LaO1−xFxBiS2 changed when the F content was increased from 0.23 to 0.46, and a nearly flat Bi–S plane was formed at x~0.46 with the appearance of superconductivity. Figure optionsDownload as PowerPoint slide