High-Pressure Synthesis of Gallium Oxonitrides and Indium Oxonitrides and their solid solutions

Applicants Professor Dr. Hubert Huppertz; Dr. Isabel Kinski
Subject Area Mineralogy, Petrology and Geochemistry
Term from 2006 to 2012
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 24799764
 

Project Description

The aim of this project is the high-pressure / high-temperature synthesis of new oxonitride phases in the system MN-M2O3 (M = Ga, In). The new materials will be synthesized via the transformation of special compounds and starting materials by applying HP/HT conditions using laser-heated diamond anvil cells, an in-situ X-ray multianvil device, and a Walker-type multianvil press. In a first step, new gallium oxonitrides with a varying molar composition will be synthesized with a close view to their structural and physical properties depending on the N/O-ratio. These investigations will be accompanied by extensive quantum mechanical calculations resulting in a target-oriented synthetic strategy, which will lead to a precise phase diagram of the system GaN-Ga2O3. In a second step, these systematic investigations will be extended on the system InN / In2O3, entering a new high-density oxonitride system, in which no compounds exist until now. Furthermore, the investigations will be expanded to solid solutions, e.g. (Al, Ga, In) oxonitrides. The planned HP/HT experiments open up a new class of materials, which is not accessible using a conventional synthetic strategy under ambient pressure conditions. Following this way, unknown areas of stability with new crystal structures and material properties will be investigated.
DFG Programme Priority Programmes
Subproject of SPP 1236:  Synthesis, "In Situ" Characterisation and Quantum Mechanical Modelling of Earth Materials, Oxides, Carbides and Nitrides at Extremely High Pressures and Temperatures
Participating Person Professor Ralf Riedel