Electrical resistivity of ultrafine-grained copper with nanoscale growth twins
Electrical resistivity of ultrafine-grained copper with nanoscale growth twins
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DOI：
10.1063/1.2799087
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发表时间：
2007-10-15
影响因子：
3.2
通讯作者：
Lu, K.
中科院分区：
文献类型：
--
作者：
Chen, X. H.;Lu, L.;Lu, K.
我们研究了高纯超细晶铜的导电性，其中含有不同浓度的纳米级生长孪晶，但具有相同的晶粒尺寸。采用脉冲电沉积法制备样品，通过调节工艺参数系统地改变孪晶的密度。在室温（RT）下，孪晶间距为15 nm的Cu样品的电阻率为1.75 μ Ω cm（电导率约为97%IACS），与粗晶（CG）纯Cu样品的电阻率相当。相同晶粒尺寸的孪晶密度的减少（孪晶片层间距分别为35和90 nm）导致电阻率从1.75 μ Ω cm增加到2.12 μ Ω cm。然而，这些Cu样品在室温下的电阻率温度系数对孪晶间距不敏感，并显示出类似于3.78 × 10（-3）/K的一致值，略小于CG Cu的电阻率温度系数（3.98 × 10（-3）/K）。Cu样品的电导率的增加主要归因于本征晶界（GB）散射，而GB缺陷和GB能量会随着孪晶密度的增加而降低。透射电子显微镜观察揭示了GB配置不同的铜样品与不同的孪晶密度。塑性变形会引起电阻率的明显增加。孪晶密度越高，在40%的轧制应变下，Cu试样的电阻率增量越大。偏离孪晶界和应变晶界都可能引起电阻率的增加。(C)2007年，美国物理学会。
We have investigated electrical resistivities of high-purity ultrafine-grained Cu containing different concentrations of nanoscale growth twins, but having identical grain size. The samples were synthesized by pulsed electrodeposition, wherein the density of twins was varied systematically by adjusting the processing parameters. The electrical resistivity of the Cu specimen with a twin spacing of 15 nm at room temperature (RT) is 1.75 mu Omega cm (the conductivity is about 97% IACS), which is comparable to that of coarse-grained (CG) pure Cu specimen. A reduction in twin density for the same grain size (with twin lamellar spacings of 35 and 90 nm, respectively) results in an increment in electrical resistivity from 1.75 to 2.12 mu Omega cm. However, the temperature coefficient of resistivity at RT for these Cu specimens is insensitive to the twin spacing and shows a consistent value of similar to 3.78x10(-3)/K, which is slightly smaller than that of CG Cu (3.98x10(-3)/K). The increased electrical resistivities of the Cu samples were ascribed dominantly to the intrinsic grain boundary (GB) scattering, while the GB defects and GB energy would decrease with increasing twin density. Transmission electron microscope observations revealed the GB configuration difference from the Cu samples with various twin densities. Plastic deformation would induce an apparent increase in the resistivity. The higher of the twin density, the higher increment of RT resistivity was detected in the Cu specimens subjected to 40% rolling strain. Both the deviated twin boundaries and strained GBs may give rise to an increase in the resistivity. (C) 2007 American Institute of Physics.