高压下二元含氮体系的稳定态的组分、结构及性质研究

项目名称： 高压下二元含氮体系的稳定态的组分、结构及性质研究

项目编号： No.11504381

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 张洁

作者单位： 中国科学院合肥物质科学研究院

项目金额： 20万元

中文摘要： 随着实验技术的提高，压力为新材料的设计与合成提供了有效途径。自单键氮在高温高压条件下合成以后，富氮物质也被作为潜在的高能密度材料，并且受到广泛的关注。为了能在现实中成功应用单键氮，本项目将从理论上做出预测，为实验提供科学依据和理论指导，加速这一目标的实现。我们将从二元含氮化合物中选取研究体系，采用遗传算法结合第一性原理方法研究物质在高压下的稳定态的组分、结构相变及性质，主要研究内容包含：（1）高压下物质的稳定态的组分及结构演化，建立压力-组分相图；（2）高压下材料的性质，包括电子结构、晶格动力学等；（3）揭示压力、组分对材料物性和N原子排布形式演化的影响。在高压下，材料内部原子之间的相互作用以及宏观的性质随压力的变化非常复杂，同时常压下的理论也面临着严峻的挑战。通过我们的研究有助于认识微观结构与宏观物理量的联系并揭示其中的物理规律，更高效地进行高能密度材料设计，缩短合成周期。

中文关键词： 高压物理；高能密度材料；稳定态组分；遗传算法；密度泛函理论

英文摘要： High pressure will open up new ways of materials design and synthesis with the development of technology. Since the single-bond nitrogen is synthesized at high temperature and high pressure, people also pay extensive attention to the nitrogen-rich materials which are potential high-energy-density-materials. In this project, our theoretical results will provide evidences for further research on nitrogen-related materials. Evolutionary algorithm and first-principles methods will be performed to investigate the stable stoichiometries, the structural phase transition and properties of binary nitrides under high pressure. Main contents are as follows. (1) Predict the stable stoichiometries and the structures of materials at high pressure, and construct the stoichiometry-pressure phase diagram. (2) Study the properties of materials, such as electronic properties, lattice dynamical properties, etc. (3) Uncover the effect of pressure and stoichiometry on the properties of materials and the evolution of nitrogen atoms. The interaction between atoms is very complicated at high pressure, which challenge the theory under ambient condition. Our results will be helpful to understand the coupling between microstructure and materials performance, and people will design materials more efficiently.

英文关键词： high pressure physics;high energy density materials;stable stoichiometries;evolutionary algorithm ;density functional theory