arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1902.01965cond-mat.mtrl-sci
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\b{eta} - NX(X=P,As,Sb)单分子膜中声子的热输运:第一性原理研究谐波与非谐波声子性质之间的相互作用

Phonon thermal transport in \b{eta}-NX (X=P, As, Sb) monolayers: a first-principles study of the interplay between harmonic and anharmonic phonon properties

Armin Taheri, Carlos Da Silva, Cristina H. Amon

摘要:

对最近出现的二维(2D)材料的热性质的研究是实现其在纳米电子器件中潜在应用的必要步骤。在这项研究中,新的\b{eta} -NX(X=P,As,Sb)单分子膜的热导率进行了研究,使用第一性原理密度泛函理论(DFT)的研究的基础上的完全解决方案的线性化Peierls-Boltzmann输运方程(PBTE)。结果表明,\b{eta} -NP、\b{eta} -NAs和\b{eta} -NSb的室温热导率分别是单元素\b{eta} -P、\b{eta} -As和\b{eta} -Sb单层的约1.1、5.5和34.0倍。声子输运分析表明,较高的声子群速度以及声子寿命是负责这种增强的晶格热导率的\b{eta} -NX(X=P,As,Sb)的二元化合物相比,单元素组VA单层。我们发现\b{eta} -NP在\b{eta} -NX(X=P,As,Sb)单分子膜中具有最小的热导率,同时它具有最小的平均原子质量,这与通常认为低质量体系具有较高热导率的假设相反。本工作证明了在确定\b{eta} -NX(X=P,As,Sb)单分子膜之间的热导率的变化的谐波和非谐波声子性质之间的权衡。发现\b{eta} -NP中较高的非谐性是该单层较低热导率的原因。

英文摘要:

The investigation of thermal properties of recently emerged two-dimensional (2D) materials is a necessary step towards fulfilling their potential applications in nano-electronics devices. In this study, the thermal conductivity of novel \b{eta}-NX (X=P, As, Sb) monolayers are investigated using a first-principles density functional theory (DFT) study based on the full solution of the linearized Peierls-Boltzmann transport equation (PBTE). The results show that the room temperature thermal conductivities of \b{eta}-NP, \b{eta}-NAs, and \b{eta}-NSb are about 1.1, 5.5, and 34.0 times higher than those of single-element \b{eta}-P, \b{eta}-As, and \b{eta}-Sb monolayers, respectively. The phonon transport analysis reveals that higher phonon group velocities as well as phonon lifetimes are responsible for such an enhancement in the lattice thermal conductivities of \b{eta}-NX (X=P, As, Sb) binary compounds compared to single-element group-VA monolayers. We found that \b{eta}-NP has the minimum thermal conductivity among \b{eta}-NX (X=P, As, Sb) monolayers, while it has the minimum average atomic mass, which is in contrast with the common assumption that lower mass systems exhibit higher thermal conductivities. This work demonstrates the trade-off between harmonic and anharmonic phonon properties in determining the variation of the thermal conductivity among \b{eta}-NX (X=P, As, Sb) monolayers. The higher anharmonicity in \b{eta}-NP is found to be responsible for the lower thermal conductivity of this monolayer.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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