Thermomechanical analysis of two-dimensional boron monolayers
Thermomechanical analysis of two-dimensional boron monolayers
复制标题
DOI：
10.1103/physrevb.93.165434
复制
发表时间：
2016-04
影响因子：
3.7
通讯作者：
T. Tsafack;B. Yakobson
中科院分区：
文献类型：
--
作者：
T. Tsafack;B. Yakobson
使用密度泛函理论计算（扰动和未扰动）以及热力学和弹道输运方程，接下来研究了二维硼单层的热性能和机械性能（${\ensuremath{\delta}}_{6}，\ensuremath{\alpha}， {\ensuremath{\delta}}_{5}$ 和 ${\ensuremath{\chi}}_{3}$ 各自的空位密度 $\ensuremath{\eta}=0$, 1/9, 1/7, 1/5) 因为它们与空位密度有关。三角形$({\ensuremath{\delta}}_{6})$片的室温声子和电子热导率分别约为石墨烯的2.06倍和6.60倍。根据纵向和横向声速计算出的杨氏模量与根据弹性常数获得的杨氏模量非常一致。值范围为 171 至 619 N/m，其中两个（$\ensuremath{\alpha}$ 片材为 619 N/m，${\ensuremath{\delta}}_{5}$ 片材为 546 N/m）超过石墨烯的杨氏模量 ($\ensuremath{\sim}340\phantom{\rule{0.16em}{0ex}}\mathrm{N}/\mathrm{m}$)。确定空位密度对定体积声子热容和声子弹道热导均具有递减作用，但对电子热容和电子弹道热导没有规律的相关性。
Using density functional theory calculations (both perturbed and unperturbed) as well as thermodynamic and ballistic transport equations, what follows investigates thermal and mechanical properties of two-dimensional boron monolayers (${\ensuremath{\delta}}_{6}, \ensuremath{\alpha}, {\ensuremath{\delta}}_{5}$, and ${\ensuremath{\chi}}_{3}$ sheets with respective vacancy densities $\ensuremath{\eta}=0$, 1/9, 1/7, 1/5) as they relate to the vacancy density. The triangular $({\ensuremath{\delta}}_{6})$ sheet's room-temperature phonon and electron thermal conductances are found, respectively, to be roughly 2.06 times and 6.60 times greater than those of graphene. The Young's moduli, calculated from longitudinal and transverse sound velocities are in good agreement with those obtained from elastic constants. Values range from 171 to 619 N/m, two of which (619 N/m for $\ensuremath{\alpha}$ sheet and 546 N/m for ${\ensuremath{\delta}}_{5}$ sheet) exceed graphene's Young's modulus ($\ensuremath{\sim}340\phantom{\rule{0.16em}{0ex}}\mathrm{N}/\mathrm{m}$). It is determined that the vacancy density has a diminishing effect on both the phonon heat capacity at constant volume and the phonon ballistic thermal conductance, but no regular correlation on the electron heat capacity and electron ballistic thermal conductance.