Author Affiliations
Abstract
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
High-pressure solid-state metathesis (HPSSM) reaction is an effective route to novel metal nitrides. A recent advance in HPSSM reactions is presented for a number of examples, including 3d transition metal nitrides (ε-Fe3N, ε-Fe3_xCoxN, CrN, and Co4Nx), 4d transition metal nitrides (MoNx), and 5d transition metal nitrides (Re3N, WNx). Thermodynamic investigations based on density functional theory (DFT) calculations on several typical HPSSM reactions between metal oxides and boron nitride indicate that the pressure could reduce the reaction enthalpy DH. Highpressure confining environment thermodynamically favors an ion-exchange process between metal atom and boron atom, and successfully results in the formation of well-crystalized metal nitrides with potential applications.
High-pressure High-pressure Solid-state metathesis reaction Solid-state metathesis reaction Metal nitrides Metal nitrides Matter and Radiation at Extremes
2018, 3(3): 95
1 四川大学原子与分子物理研究所,成都 610065
2 广西大学物理科学与工程技术学院,南宁 530004
3 四川大学物理与科学技术学院,成都 610065
4 四川大学高能量密度物理与技术教育部重点实验室,成都 610065
本工作通过高压固相复分解反应(HPSSM)合成块体Re3N。利用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和能量色散X射线分析(EDS)对高压样品进行结构表征与元素成分确定,结果表明利用HPSSM法合成的Re3N具有较高的晶体质量。在77 K到873 K温度范围内利用拉曼散射研究Re3N的晶格振动特性。基于三(四)声子耦合模型,研究Re3N拉曼声子模频率的红移和拉曼峰的宽化现象,结果表明高温条件下Re3N拉曼散射效应中三声子耦合过程占主导。高压同步辐射研究表明Re3N具有很高的体弹模量(B0=417 GPa),是一种潜在的超硬材料。
5d金属氮化物 拉曼散射 高压同步辐射 5d metal nitrides Raman scattering high-pressure synchrotron radiation
