On the structure and microstructure of “PbCrO3”

The reliability factors of a Rietveld X-ray powder refinement of PbCrO3 could be improved by considering the lead ion in a multi-minimum potential displaced from its special position. These studies coupled to EDX analysis show a certain lead deficiency. Electron diffraction and high-resolution electron microscopy reveal that the microstructure of this material is a rather complex perovskite superstructure that presents a compositional modulation, within a microdomain distribution. The proposed supercell is ∼ap×3ap×(≈14-18)ap∼ap×3ap×(≈14-18)ap.

Model of the structure of PbCrO3 obtained by electron microscopy and diffraction.Figure optionsDownload as PowerPoint slide