高压下TiC力学与光学性能的理论研究

Theoretical study on phase transition, mechanical, electricaland optical properties of TiC under high pressure

通过第一性原理计算的方法探究了TiC的NaCl相在0~571.6 GPa的压力范围内的力学与光学性能。研究了TiC的NaCl结构的静态和动态稳定性,得到TiC的相变压强为571.6 GPa,并且通过声子谱的计算可以看出TiC在相变压强范围内具有动态稳定性。各向异性分析可以看出压力作用会导致TiC的各向异性程度增加。系统地研究了TiC的光学特性,包括介电函数、吸收、反射、电导率以及损失光谱,希望为扩展TiC在红外辐射陶瓷和光敏传感器中的应用提供帮助。

In this paper,the mechanical and optical properties of the NaCl structure of TiC in the pressure range from 0 to 571.6 GPa are explored by first-principles calculations.Firstly,the static and dynamic stability of NaCl structure of TiC are studied,and its maximum stable pressure is 571.6 GPa.The result of phonon spectrum shows that TiC has dynamic stability in the phase transition pressure range.The anisotropy analysis shows that the pressure action leads to an increase in the degree of anisotropy of TiC.Particularly,the optical properties of TiC including dielectric function,absorption,reflection,conductivity and loss function are investigated systematically,hoping to be helpful to extend the application of TiC in infrared optical ceramics and photosensitive sensor.