摘要
为研究电介质薄膜中的导热机制以及薄膜厚度对导热系数的影响 ,以氩的 FCC晶体为模型 ,采用分子动力学方法计算了厚度约为 2～ 10 nm的薄膜的法向导热系数。计算得到对应于 12 0 K的薄膜导热系数显著低于大体积实验值 ,并随薄膜厚度的减小而降低 ;即纳米薄膜的晶格导热系数具有明显的尺寸效应。当薄膜厚度减小至纳米量级时 ,即使在较高温情况下 1.3ΘD,晶体边界对声子的散射也将起重要作用。对氩晶体分别选取了 L ennard- Jones作用势和一种软球作用势 。
The thermal conductivity in the normal direction of nanoscale thin dielectric films is predicted using molecular dynamics calculations for the face centered cubic (FCC) argon crystal. For film thicknesses of 2~10 nm for which real measurements can not yet be implemented, the lattice thermal conductivity is shown to decrease greatly with size compared with bulk experimental data. This size effect demonstrates that phonon boundary scattering in thin films may also be very significant at high temperatures near or even above the Debye temperature ( 1.3Θ D). The influence of different potential models is examined by comparing results from the Lennard Jones potential and a soft sphere potential.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2001年第8期83-86,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目 ( 5 9776 0 13)
关键词
导热系数
尺寸效应
电介质薄膜
分子动力学
thermal conductivity
size effect
thin dielectric film
molecular dynamics
