AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China.
Nanotechnology. 2010 Feb 26;21(8):85703. doi: 10.1088/0957-4484/21/8/085703. Epub 2010 Jan 25.
We measured the thermal and electrical conductivities of nanoporous Au thin foils in the temperature range 93-300 K. Resulting from the nanoscale microstructure, the two types of conductivities are both temperature dependent and significantly lower than those of bulk Au. However, the corresponding Lorenz number is strikingly similar to that of bulk Au, indicating that the Wiedemann-Franz law holds perfectly well for nanoporous metals in this temperature range. Compared to the bulk value, the Debye temperature of nanoporous Au is decreased. We predict the theoretical Debye temperature of nanoporous Au by its relation to the elastic constants. The present results indicate that the nanoporous Au foils should be comprised of macroscopic, single-crystalline porous grains rather than nanocrystals.
我们测量了纳米多孔金薄膜在 93-300 K 温度范围内的热导率和电导率。由于纳米尺度的微结构，这两种电导率都与温度有关，并且明显低于体相金的电导率。然而，相应的洛伦兹数与体相金的洛伦兹数惊人地相似，这表明威德曼-弗朗兹定律在这个温度范围内对纳米多孔金属完全适用。与体相值相比，纳米多孔金的德拜温度降低了。我们通过与弹性常数的关系来预测纳米多孔金的理论德拜温度。目前的结果表明，纳米多孔金箔应该由宏观单晶多孔晶粒组成，而不是纳米晶体。
