Chemistry Weekly Seminar - Allison Wustrow, Universite de Sherbrooke

Title

Unlocking the Potential of Solid State Reactions: High Temperature Synthesis of YMnO3

Abstract

Functional materials play an important role in technological development, from energy storage to catalysts to quantum materials. However, many of the inorganic solids which play key roles in new technologies are not solution processible, requiring them to be synthesized entirely in the solid state. As solution chemistry has developed at a rapid pace in the last two hundred years, allowing for incredible amounts of synthetic control, solid state synthesis has focused on a high temperature paradigm which primarily targets only thermodynamically stable phases. In the 21^st century, a renewed focus has been placed on understanding reaction pathways of these reactions in order to exert increased synthetic control. Here we discus the synthesis of YMnO₃ as a test system to determine which factors are important in the design of solid-state reactions. The ternary oxide was formed through a metathesis reaction, where a halide salt was formed in addition to the targeted product. These reactions occur at reduced temperatures (500-600^oC) and through varying the salt product we are able to selectively synthesize both the hexagonal and the metastable orthorhombic polymorph of YMnO₃. Using ex post facto diffraction measurements to track reactions at different temperatures, we define the metrics necessary for rational design of solid-state chemical reactions.

Date:    Friday, November 4

Time:    1:30 pm

Place:    ARTS 146

Note:    Dr. Wustrow will be joining remotely via Zoom.