Abstract:

High-pressure synthesis routes enable the access to a broad variety of novel nitride-based materials with properties far beyond that of the state of the art. The ultimate goal of our studies is to advance the knowledge and understanding of inorganic nitrides, oxynitrides and nitride-based (nano)composites synthesized under high-pressure and high temperature conditions. The discovery of novel nitrides will open space for new fundamental materials science studies on the one hand and application-oriented research on the other hand. Our research is part of the materials driven technology, which is an essential requirement for the future demands with respect to the development of new technologies. Binary, ternary and multinary nitrides or oxynitrides are in the focus of our studies. Theoretical predictions of novel metal or non-metal nitride solid-state structures guide the experimental studies. The use of a large volume press allows to produce new materials in amounts suitable for further mechanical and functional characterization. Molecular single source precursors are synthesized and transformed to inorganic solid nitrides as starting materials. Special emphasis is placed on (i) fundamental questions regarding pressure-temperature phase relations, (ii) nitrides, which have been predicted but not synthesized yet, and (iii) nitride-based (nano)composites which combine at least two binary high-pressure phases in one material. The novel nitrides are evaluated in terms of their challenging and technologically relevant properties including (i) thermodynamic stability/metastability and (ii) structural (hardness) as well as functional (optoelectronic) properties. Finally, our research contributes to extend the “Nitride World” and to deliver perspective materials based on the inorganic nitride family with advanced functionality and exceptional levels of performance for application in the key technologies of the 21^st century.

Bio:

Prof. Riedel got a PhD degree in Inorganic Chemistry in 1986 at the University of Stuttgart. After a Postdoc period at the Max-Planck Institute for Metals Research in Stuttgart, he became Full Professor at the Institute of Materials Science at the Technical University of Darmstadt in 1993. He is an elected member of the World Academy of Ceramics, Fellow of the American Ceramic Society, the European Ceramic Society as well as Fellow of the School of Engineering at The University of Tokyo in Japan. Prof. Riedel was awarded with the Gold Medal for Merits in Natural Sciences and with an honorary doctorate of the Slovak Academy of Science as well as with the Gustav Tammann Prize of the German Society of Materials Science (DGM). He received honorary Professorships at the Tianjin University in Tianjin, China in 2009 and at the Xiamen University in Xiamen, China, in 2021. Prof. Riedel received the Innovation Talents Award of Shaanxi Province, China in 2019 as well as the Great Wall Award from China in 2023. He is Guest Professor at the University of Tokyo in the group of Prof. Ikuhara, Japan and was awarded with the International Ceramics Prize 2020 for “Basic Science” of the World Academy of Ceramics. He He is Editor in Chief of the Journal of The American Ceramic Society and of Ceramics International. His current research interest is focused on two research areas, namely i) molecular synthesis of advanced structural and functional ceramics for ultra-high temperature and energy-related applications as well as ii) ultrahigh pressure materials synthesis.