High-(p,T) syntheses and characterisation of binary transition metal carbides and nitrides of the period 6 elements with atomic numbers 73-79

原子序数 73-79 的 6 周期元素二元过渡金属碳化物和氮化物的高 (p,T) 合成和表征

• 批准号: 139797560
• 负责人: Dr. Alexandra Friedrich
• 金额: --
• 依托单位: Fachrichtung Mineralogie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/139797560?language=en
• 关键词: syntheses; characterisation; binary; transition; metal

Carbides and nitrides of heavy transition metals are possible candidates as ultrahard and ultrastiff materials with ultrahigh melting temperatures. It is proposed here to study the formation of novel transition metal carbides and nitrides of the period 6 elements with atomic numbers from 73 to 79 by reaction of the elements at high pressures and high temperatures. First focus will be on the formation of tantalum and rhenium nitrides, and osmium and iridium carbides. Subsequent studies will concentrate on the formation of gold carbide and nitride. Our previous studies have already indicated the existence of a novel high-(p,T) tantalum nitride. The crystal structure of a poorly characterised osmium carbide is discussed controversially. The existence of the other carbides and nitrides has not even been investigated up to now. The final aim is the understanding of the crystal chemistry and structure-property relations in this interesting class of compounds. The formation and stability fields will be determined in the laser-heated diamond anvil cell. Phases will be characterised by powder X-ray diffraction, quantum-mechanical calculations, and Raman spectroscopy. Recrystallisation experiments are aimed at the production of microcrystals for structure determination by micro X-ray diffraction. Larger quantities of sample material will be produced by multi anvil press syntheses for powder neutron diffraction, chemical analyses, and measurements of the physical properties of the reaction products.

重过渡金属的碳化物和氮化物是具有低熔点的超硬和超硬材料的可能候选者。本文拟研究原子序数为73 ~ 79的第6周期元素在高压高温下反应生成新型过渡金属碳化物和氮化物。第一个重点将是钽和氮化锇，以及锇和铱的碳化物的形成。随后的研究将集中在金的碳化物和氮化物的形成。我们以前的研究已经表明存在一种新的高（p，T）氮化钽。晶体结构的一个很差的特点碳化锇讨论有争议。其他碳化物和氮化物的存在至今尚未被研究。最终的目的是理解这类有趣的化合物的晶体化学和结构-性质关系。在激光加热金刚石对顶砧装置中测定了形成场和稳定场。相将通过粉末X射线衍射、量子力学计算和拉曼光谱来表征。重结晶实验的目的是生产微晶，通过微X射线衍射进行结构测定。大量的样品材料将通过多砧压机合成产生，用于粉末中子衍射、化学分析和反应产物物理性质的测量。