过渡金属化合物OsB2与OsO2低压缩性的第一性原理计算研究

利用基于密度泛函理论平面波赝势法的第一性原理计算, 研究了过渡金属化合物OsB₂和OsO₂的金红石相、黄铁矿相与萤石相三种结构在高压下的状态方程和结构特性以及OsO₂可能的高压相变.理论计算结果支持OsB₂与OsO₂的萤石相是潜在超低可压缩性的硬性材料.同时，也分析了它们的电子结构，力求理解大体变模量和高硬度的微观机制.结果表明，可以利用过渡金属高的价电子浓度，掺入硼、氧、碳、氮等轻的元素形成强的关键词：过渡金属化合物密度泛函理论低压缩性高压

First principles studies of low-compressibility of transition-metal compounds OsB2 and OsO2

By the first principles plane-wave pseudopotential calculations based on the density functional theory, we studied the equations of states and structural properties of transition metal compounds OsB₂ and OsO₂ and the possible high pressure phase transitions of OsO₂. Three (rutile, pyrite and fluorite) phases of OsO₂ are studied under high pressure. The calculated results support the opinion that OsB₂ and the fluorite phase of OsO₂ should be potential ultralow-compressible hard materials. The microscopic mechanism of large bulk modulus and high hardness can be understood from the calculated electronic structures. It is therefore suggested that incorporating light elements (boron, oxygen, carbon or nitrogen) into transition metals with high valence electron densities is possibly a new way to prepare superhard materials.