Nitride chemistry of geomaterials: Formation, crystal structures and properties of multinary metal nitrides prepared at high pressures

该项目的目的是在高压和高温下从富含金属的熔体中制备新的二元和多元氮化物，并随后对所得化合物进行表征。实验最好在合作伙伴的理论预测之后设计。新化合物的特性包括晶体结构和组成、物理性能（如磁性能、电阻率、硬度以及压缩模量）。 该项目首先从先前制备和良好表征的二元相开始研究Fe <$N系统的高压相。在对这些相在高压和高温下的行为有了很好的理解之后，该系统将随后扩展到Fe <$N <$C和Fe <$N <$C <$O。在进一步的步骤中，将研究涉及不同3d金属和其他金属组分的示例性组合物，优选在前面的理论预测之后。该项目的一个重要部分将涉及开发适当的无机前体化合物，用于金刚石压砧单元中的原位实验，并开发适当的氮源和氧源，用于多砧压机中的非原位压力制备实验。这一部分涉及这些前体的物理和化学性质的研究和高压阶段的实验条件的优化。

The project aims to the preparation of new binary and multinary nitrides from metal-rich melts under high pressures and temperatures and the subsequent characterisation of the obtained compounds. The experiments are preferably designed after the theoretical prediction from the cooperation partner. Characterisation of new compounds comprises the crystal structure and composition, physical properties as magnetic behaviour, electrical resistivity, hardness as well as compression module. The project starts with the investigation of the high pressure phases of the Fe¿N system from previously prepared and well characterised binary phases. After a good understanding of the behaviour of these phases at high pressure and temperature is achieved, the system will be subsequently extended to Fe¿N¿C and Fe¿N¿C¿O. In a further step exemplary compositions involving different 3d-metals and further metallic components will be studied, preferably after preceding theoretical prediction. An important part of the project will deal with the development of adequate inorganic precursor compounds for in-situ experiments in diamond anvil cells and proper nitrogen and oxygen sources for ex-situ pressure preparation experiments in a multi-anvil press. This part involves the study of the physical and chemical properties of these precursors and the optimisation of experimental conditions for the high-pressure phases.