Prof. Ralf Riedel [Technical University of Darmstadt, Germany]

Title: High-Pressure Materials Synthesis – A Guideline for the Discovery of Advanced Ceramic Nitrides

Language:  English presentation

Time: 10:00 - 11:00 AM, October 23, 2024

Place: Onsite：Conference room A417, HPSTAR (Beijing)             

           Online:  Tencent Meeting: https://meeting.tencent.com/dm/u6jluJFqk5qF  Meeting ID: 654-228-124

Host:  Prof. Toshimori Sekine

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 21st century.

Ref.:Riedel, R, High-pressure materials synthesis-A guideline for the discovery of advanced ceramic nitrides, Ceramics International 49 (2023), 24102-24111.

Biography of the Speaker:

Main Research Fields

- Si-based polymers

- Synthesis and properties of novel functional and structural ceramics

- Polymer derived ceramics for energy applications

- High pressure & high temperature materials synthesis

- Foundation of the “Joint International Research Laboratory of Ultrahigh Ceramic Matrix Composites”  between TU Darmstadt and the Northwestern Polytechnical University in Xi´an, China, in 2017