Ti_3(Ge_(1-x)Si_x)C_2固溶体力学和热力学性能的第一性原理研究

采用基于密度泛函理论(DFT)的第一性原理平面波超软赝势方法,系统研究了Ti_3(Ge_(1-x)Si_x)C_2(x=0, 0.5, 1)固溶体的晶体结构、弹性性质以及热力学性能.研究结果表明,Ti_3(Ge_(1-x)Si_x)C_2体系均具有力学和热力学稳定结构,并且为脆性材料;Ti_3(Ge_(1-x)Si_x)C_2固溶体的力学性能随Si含量的增加而提高;Ti_3(Ge_(1-x)Si_x)C_2固溶体在室温下具有稳定的晶格结构和较高的晶格热导率,有望用于一些需要良好散热性能电子元器件的封装材料.

First-principles investigations of mechanical and thermal properties of Ti 3 (Ge1-xSix)C2 solid solutions

The thermodynamic stability, mechanical and thermal properties of the recently synthesized Ti 3 (Ge1-xSix)C2 solid solutions are studied Using first-principles calculations. The calculated results show that all these compounds have a thermodynamically stable structure, and are brittle materials. At the same time, they also show the characteristics of metals. The mechanical properties of Ti3(Ge1-xSix)C2 solid solution can increase with the increase of the concentration of Si. In addition, the lattice thermal conductivity of Ti3(Ge1-xSix)C2 solid solution at 300K is slightly lower than that of metal, which is the same as the thermal conductivity of most alloys. It can be used as a thermal conductive material at room temperature.