沿分子链的长度依赖性热输运。

Length-dependent thermal transport along molecular chains.

作者信息

Meier T, Menges F, Nirmalraj P, Hölscher H, Riel H, Gotsmann B

机构信息

IBM Research-Zurich, Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland and Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.

IBM Research-Zurich, Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland and Nanotechnology Group, ETH Zürich, Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland.

出版信息

Phys Rev Lett. 2014 Aug 8;113(6):060801. doi: 10.1103/PhysRevLett.113.060801.

DOI:10.1103/PhysRevLett.113.060801

PMID:25148312

Abstract

We present heat-transport measurements conducted with a vacuum-operated scanning thermal microscope to study the thermal conductance of monolayers of nine different alkane thiols self-assembled on Au(111) surfaces as a function of their length (2 to 18 methylene units). The molecular thermal conductance is probed in a confined area with a diameter below 10 nm in the contact between a silicon tip and the self-assembled monolayer. This yields a pWK(-1) sensitivity per molecule at a tip temperature of 200-300 °C versus the gold at room temperature. We found a conductance variance of up to a factor of 3 as a function of alkane chain length, with maximum conductance for a chain length of four carbon atoms.

摘要

我们展示了利用真空操作扫描热显微镜进行的热输运测量，以研究在Au(111)表面自组装的九种不同烷硫醇单分子层的热导率与其长度（2至18个亚甲基单元）的关系。在硅探针与自组装单分子层的接触中，在直径小于10 nm的受限区域内探测分子热导率。这在200 - 300°C的探针温度与室温下的金之间产生了每分子pWK(-1)的灵敏度。我们发现，作为烷烃链长度的函数，电导率变化高达3倍，链长为四个碳原子时电导率最大。