111th MSL Lecture (Professor James Neilson) 10/25

• Time and Date: October 25, 2019 16:00-17:30
• Place: Tokyo Institute of Technology, Suzukake Campus, H2 bldg. 2F Meeting Room
• Speaker: Professor James Neilson（Department of Chemistry, Colorado State University）
• 111th MSL Lecture Program
• Language: English

Enabling Prescriptive Synthesis of Metastable Ternary Oxides with Mixed Anions

Complex oxides enable a diverse set of electronic properties. However, we do not yet know how to prescriptively synthesize desired compositions or polymorphs of materials, particularly if they are metastable. Metathesis (or double-exchange) reactions are well suited to address synthesis questions pertaining to atomic transport and permit the identification of incipient stages of phase differentiation in solid-state reactions. As an example, the reaction, A₂CO₃ + Mn₂O₃ + YCl₃, where A = Li, Na, or K, yields different Y-Mn-O products (and polymorphs) depending on which spectating alkali is present. From a combination of in situ and ex situ analysis of myriad synthesis reactions combined with first-principles calculation of thermodynamic parameters, we identify competent intermediates that enable kinetic control of the reaction, such as the phases LiMnO₂ and YOCl. These results allow us to establish the critical processes in solid-state reaction pathways that enable, or hinder, prescriptive synthesis.

References：
Paul K. Todd and James R. Neilson, J. Am. Chem. Soc. 141, 1191-1195 (2019)

• MSL: 111th MSL Lecture (Professor James Nielson)

• Azuma-Yamamoto Lab.