Effect of Electrical Contact Resistance on Measurement of Thermal Conductivity and Wiedemann-Franz Law for Individual Metallic Nanowires.
Effect of Electrical Contact Resistance on Measurement of Thermal Conductivity and Wiedemann-Franz Law for Individual Metallic Nanowires.
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电接触电阻对单个金属纳米线热导率和维德曼-弗朗兹定律测量的影响
DOI：
10.1038/s41598-018-23291-9
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发表时间：
2018-03-20
影响因子：
4.6
通讯作者：
Chen Y
中科院分区：
文献类型：
--
作者：
Wang J;Wu Z;Mao C;Zhao Y;Yang J;Chen Y
金属纳米结构的电学和热学性质已经引起了相当大的基础和技术兴趣。最近的研究证实，当尺寸与电子平均自由程相当或甚至小于电子平均自由程时，电导和热导急剧下降。然而，Wiedemann-Franz定律在这些纳米结构中的验证仍然存在激烈的争论。由双探针测量得到的洛伦兹数远大于由四探针测量得到的洛伦兹数。在这里，我们报道了用双探针和四探针配置测量的单个银纳米线的电学和热学性质。测量的接触电阻几乎与温度无关，表明接触处的电子输运以弹道为主。当接触热阻的影响减弱时，由四探针构型测得的洛伦兹数与Sommerfeld值相当，验证了Wiedemann-Franz定律在单晶状银纳米线中成立。相比之下，在双探头测量中，导电率变小，导热系数变大，证实了接触电阻会引入较大的误差。本研究从实验上证明了从不同的金属纳米结构获得的洛伦兹数中令人沮丧的大跨度的合理解释。
The electrical and thermal properties of metallic nanostructures have attracted considerable fundamental and technological interests. Recent studies confirmed a dramatic decrease in the electrical and thermal conductivities when the dimension is comparable or even smaller than the electron mean free path. However, the verification of the Wiedemann-Franz law in these nanostructures remains hotly debated. The Lorenz number obtained from the two-probe measurement is found to be much larger than that from the four-probe measurement. Here, we reported the electrical and thermal properties of the individual silver nanowires measured by the two-probe and four-probe configurations. The measured electrical contact resistance is found to be nearly temperature-independent, indicating a ballistic-dominant electronic transport at the contacts. When the effect of thermal contact resistance is diminished, the Lorenz number measured by the four-probe configuration is comparable to the Sommerfeld value, verifying that the Wiedemann-Franz law holds in the monocrystalline-like silver nanowire. Comparatively, the derived electrical conductivity becomes smaller and the thermal conductivity becomes larger in the two-probe measurement, confirming that the electrical contact resistance will introduce a large error. The present study experimentally demonstrates a reasonable explanation to the discouragingly broad span in the Lorenz number obtained from different metallic nanostructures.
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影响因子：
4.6
作者：
Cheng Z;Liu L;Xu S;Lu M;Wang X
通讯作者：
Wang X
影响因子：
4
作者：
Ou, M. N.;Yang, T. J.;Lai, S. J.
通讯作者：
Lai, S. J.
影响因子：
3.2
作者：
Shi, Li;Zhou, Jianhua;McEuen, Paul L.
通讯作者：
McEuen, Paul L.
晶界散射对多晶金纳米薄膜电导率和导热率的影响
影响因子：
3.7
作者：
Zhang, Q. G.;Cao, B. Y.;Takahashi, K.
通讯作者：
Takahashi, K.
影响因子：
56.9
作者：
PASCUAL, JI;MENDEZ, J;CHENG, HP
通讯作者：
CHENG, HP