SESSION: SolidStateChemistryWedPM4-R7 |
Kanatzidis International Symposium (4th Intl. Symp. on Materials/Solid State Chemistry and Nanoscience for Sustainable Development) |
Wed. 23 Oct. 2024 / Room: Ariadni A | |
Session Chairs: Pantelis Trikalitis; Gerasimos S. Armatas; Student Monitors: TBA |
We had found it being somewhat surprising that, in the following sequence of “simple” perovskites: PbTiO3 is tetragonal (c/a = 1.064), PbVO3 is also tetragonal with quite a higher tetragonal ratio (c/a =1,229) while PbCrO3 is cubic (¡) [1]. A detailed structural and compositional analysis by X ray and electron diffraction and high-resolution electron microscopy coupled with EDS, of this High-Pressure phase, has shown that the reliability factors of the 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. Also, the microstructure of this material is a rather complex perovskite superstructure that presents a compositional modulation, within a microdomain distribution in a slightly lead deficient material [2]. The proposed supercell is ~ap x 3ap x (~14-18)ap; with ap being the average cubic perovskite parameter [3].