FOR 1600:  Chemistry and Technology of the Ammonothermal Synthesis of Nitrides

• Subject Area: Thermal Engineering/Process Engineering ; Chemistry ; Computer Science, Systems and Electrical Engineering
• Term: from 2011 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 182356696

Objective of the research project is to develop a basic understanding of the ammonothermal synthesis to understand and influence the processes involved, and to derive scientific insight in order to achieve the fundamentals for the growth of high quality nitride crystals. Based on these studies of the synthesis of technologically interesting, new nitrides and related compounds, this synthesis route, the chemical processes that take place in liquid and supercritical ammonia, shall be developed step by step and applied. Additionally, for the determination of thermodynamic and crystallisation data, in situ monitoring devices shall be methodically developed subject to technical realisation.
For the first time, it should be possible to trace the ongoing process in the reactors at typical ammonothermal synthesis conditions (up to 300 MPa and 600 °C) using optical and radiographic analysis. For this purpose, new equipment shall be developed, which includes a special sampling method to allow chemical balancing. Thus, a new door to findings in the field of ammonothermal synthesis will be opened that will further lead to the development of new substances and materials.
Therefore, the main objective is to clarify the processes involved in ammonothermal synthesis to develop optimal experimental equipment and apparatuses to support this objective and ultimately to obtain the fundamentals for a systematic crystal growth in the ammonothermal system as well as developing new materials and optimal crystallisation processes.

• DFG Programme: Research Units

Projects

• Ammonothermal synthesis of binary and multinary nitrides, amides and imides of Ga, Al, Si and Ge (Applicant Schnick, Wolfgang )
• Coordination project (Applicant Schlücker, Eberhard )
• Crystal Growth of nitride single crystals of high purity with the ammonothermal method (Applicant Meissner, Elke )
• Development of special high pressure and high temperature equipment and spectroscopic in situ investigations (Applicant Schlücker, Eberhard )
• In situ visualization of the ammonothermal crystallization process using X-ray measurement techniques (Applicant Wellmann, Peter )
• Intermediates during Ammonothermal Synthesis of Crystals of Binary and Higher Metal Nitride Semiconductor Materials (Applicant Niewa, Rainer )
• Investigation of dissolution- and crystrallization equilibria as a basis for the ammonothermal crystal growth of nitrides (Applicant Schwieger, Wilhelm )

• Spokesperson: Professor Dr.-Ing. Eberhard Schlücker