Size-dependent resistivity of metallic wires in the mesoscopic range - art. no. 075414
Size-dependent resistivity of metallic wires in the mesoscopic range - art. no. 075414
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DOI：
10.1103/physrevb.66.075414
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发表时间：
2002-08-15
影响因子：
3.7
通讯作者：
Engelhardt, M
中科院分区：
文献类型：
--
作者：
Steinhögl, W;Schindler, G;Engelhardt, M
当导体的横向尺寸接近介观范围时，观察到电阻率与块体材料的偏差。当导线的横向尺寸在传导电子的平均自由程范围内或以下时，尺寸效应就开始发挥作用。为了研究两种横向尺寸系统的尺寸效应，我们在SiO2基体中制备了宽度在40 ~ 800 nm之间的铜线。在77 ~ 573 K的温度范围内测量了导线的电阻。随着导线宽度的减小，电阻率随尺寸的增大而增大。对于最窄的导线，电阻率比铜体积值（1.75 μ ω cm）高2.6倍。利用半经典模型，将实验数据与理论预测在整个研究范围内的尺寸和温度进行了比较。该模型包括导电电子在金属丝表面和晶界的扩散散射。理论与实验数据非常吻合。这样就得到了与尺寸有关的电阻率的连贯图像。
As the lateral dimension of conductors approaches the mesoscopic regime, deviations of electric resistivity from that of bulk material are observed. Size effects come into play as the lateral dimension of the wire is in the range of the mean free path of the conduction electrons and below. In order to probe the size effects in systems confined in both lateral dimensions copper wires with widths ranging from 40 to 800 nm were prepared in a SiO2 matrix. The resistance of the wires was measured in the temperature range from 77 to 573 K. A size-dependent increase of the resistivity was found for decreasing wire widths. For the narrowest wires the resistivity is a factor of 2.6 higher than the copper bulk value (1.75 muOmega cm). The experimental data was compared to theoretical predictions over the whole investigated range of size and temperature using a semiclassical model. The model includes diffusive scattering of the conduction electrons at the surface and the grain boundaries of the wire. Very good agreement of theory with experimental data was found. In this way a coherent picture of the size dependent resistivity has been obtained.