Coupled Compositional and Displacive Modulations in KLaMnWO6 Revealed by Atomic Resolution Imaging

Susana Garcia-Martin; Graham King; Esteban Urones-Garrote; Patrick M Woodward

doi:10.1021/jacs.1c07426

Coupled Compositional and Displacive Modulations in KLaMnWO₆ Revealed by Atomic Resolution Imaging

J Am Chem Soc. 2021 Nov 17;143(45):19121-19127. doi: 10.1021/jacs.1c07426. Epub 2021 Nov 3.

Authors

Susana Garcia-Martin¹, Graham King², Esteban Urones-Garrote¹, Patrick M Woodward³

Affiliations

¹ Departamento de Química Inorgánica. Facultad de Ciencias Químicas. Universidad Complutense, Madrid 28040, Spain.
² Canadian Light Source, 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada.
³ Department of Chemistry and Biochemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States.

PMID: 34730339
DOI: 10.1021/jacs.1c07426

Abstract

Complex compositional and displacive modulations of the crystal structure of KLaMnWO₆ are imaged with atomic resolution by means of scanning transmission electron microscopy (STEM). This oxide is stabilized by cation vacancies leading to a La_1+x/3K_1-xMnWO₆ stoichiometry. Compositional modulation on both the K and La layers are revealed in the high-angle annular dark-field STEM (HAADF-STEM) images. The compositional modulation within the La layer is coupled with the modulation of the octahedral tilting, which is exposed by imaging of the anion sublattice in annular bright-field STEM (ABF-STEM) images. These complex modulations are accommodated in a 5√2a_p × 5√2a_p × 2a_p perovskite-type structure.