Due to their simple structure and compositional diversity, vacancy-ordered double perovskites have emerged as excellent model systems for examining structure-property relationships in halide perovskites. For example, in the compounds A2RuX6, altering the identity of the A- and X-site ions and studying the optical and magnetic properties of the resulting compounds has provided a more complete understanding of the bonding and role of spin-orbit coupling in these materials. Here, we present work on the synthesis and characterization of the family of compounds A2MoOxX6–x (0 ≤ x ≤ 2). We find that different synthesis strategies result in varying oxygen concentrations in these materials, and therefore differing amounts of Mo(IV), Mo(V), and Mo(VI). In turn, the composition can be monitored via diffraction methods, X-ray photoelectron spectroscopy (XPS), magnetic measurements, Raman, and UV-vis spectroscopy. Knowledge of the compositions of these materials and the oxidation states present are used to rationalize observed trends in symmetry, optical absorption, magnetism, and phase transitions.

Tuning magnetism and optical properties in the oxyhalide solid-solutions A2MoOxX6–x

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.