二维Mo2C的晶格热导率的第一性原理研究

Mo2C是构建Mxene基器件的重要材料之一，对Mo2C二维材料声子输运的理解非常必要。文章结合第一性原理方法和声子玻尔兹曼输运方程，研究了二维Mo2C材料的晶格热导率。研究表明，室温下二维Mo2C导热系数非常低，其锯齿方向和扶手椅方向的晶格热导率分别为7.20 和 5.04 W/mK。计算了声学振动和光学振动模式对晶格热导率的贡献，揭示总热导率主要由面内声学横波的振动模式所贡献。还进一步计算了声子群速度、声子弛豫时间、三声子散射空间和模式格林艾森参数，发现二维Mo2C中的声子群速度和声子弛豫时间对晶格传输有重要的影响。

First-Principles Study of lattice thermal conductivity of 2D Mo2C

A fundamental understanding of phonon transport in 2D-Mo2C is crucial to predict the thermal performance in potential Mxene-based device. By combining first-principle calculation and phonon Boltzmann transport equation, we obtain the lattice thermal conductivity of 2D-Mo2C. A much lower thermal conductivity (7.20 and 5.04 Wm-1K-1 in zigzag and armchair direction) is observed in 2D-Mo2C at room temperature. The contributions of acoustic and optical phonons to the lattice thermal conductivity are evaluated. The transverse acoustic phonons contribute mainly to the total thermal conductivity. Furthermore, the total phase space for phonon group velocity, relaxation time, three-phonon processes and Grüneisen parameters are further investigated. The phonon group velocity and relaxation time are unveiled to be the key ingredients of thermal transport in 2D-Mo2C.