The State Key Lab of
High Performance Ceramics and Superfine Microstructure
Shanghai Institute of Ceramics, Chinese Academy of Sciences
中 国 科 学 院 上 海 硅 酸 盐 研 究 所 高 性 能 陶 瓷 和 超 微 结 构 国 家 重 点 实 验 室
Inorganic chalcogenide solids: from discovery to design and applications
Mercouri G. Kanatzidis
Northwestern University, USA
In this talk I will describe how we design, approach, perform, observe, understand, and engineer the formation of compounds from inorganic melts. I will focus on how novel chalcogenides can form using the fluxes but also design concepts such as the “counterion effect”, “dimensional reduction” and “panoramic synthesis”. For example in systems such as K-Cu-S and K-Sn-S compounds that span metallic and insulating behavior can be isolated. Common structural motifs within these materials systems belie structural precursors in the melt that may be controlled by tuning reaction conditions and composition. Using complementary techniques of in-situ x-ray diffraction we can create time-dependent maps of reaction space and probe the mobile species present in melts. An important link in our chemistry is the concept of a ‘functional group,’ a fragment of a few atoms that behaves predictably when combined with other functional groups or reagents. When well defined building blocks are present and stable in the reaction, prospects for increased structural diversity and product control increase substantially. The stabilization of a particular building block is accomplished with the tuning of flux composition which controls Lewis basicity and redox potential. In such tunable and dynamic fluxes, synthesis can be directed towards new materials. I will highlight routes toward the ultimate goal of targeted materials synthesis by controlling inorganic melt chemistry.
Mercouri G. Kanatzidis is a Professor of Chemistry and of Materials Science and Engineering at Northwestern University in Evanston, IL. He also has a senior scientist appointment at Argonne National Laboratory. His interests include the design and synthesis of new materials with emphasis on systems with highly unusual structural/physical characteristics or those capable of energy conversion, energy detection, environmental remediation, and catalysis. After obtaining his B.Sc. degree from Aristotle University in Greece, he received his Ph.D. degree in Chemistry from the University of Iowa and was a postdoctoral research fellow at the University of Michigan and Northwestern University. He holds a Charles E. and Emma H. Morrison Professor Chair at Northwestern University.