Temperature dependence of electrical properties of electrodeposited Ni-based nanowires
Temperature dependence of electrical properties of electrodeposited Ni-based nanowires
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DOI：
10.1088/1742-6596/902/1/012010
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
R. Dost;D. Allwood;B. Inkson
中科院分区：
文献类型：
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作者：
R. Dost;D. Allwood;B. Inkson
研究了退火对圆柱形镍基纳米线的微结构和电学性能的影响。通过电化学沉积分别将标称直径为200 nm的镍和标称直径为70 nm的坡莫合金（Py）的纳米线制成聚碳酸酯和阳极氧化铝的纳米多孔模板。对生长态纳米线和在650°C下热处理的纳米线进行表征。所生长和退火的纳米线的透射电子显微镜和衍射成像显示具有≤8 nm（Ni）和≤20 nm（Py）晶粒的初始纳米晶体结构的温度相关晶粒生长朝向具有高达约160 nm（Ni）和70 nm（Py）晶粒尺寸的较粗多晶，后者受到纳米线宽度的限制。在扫描电子显微镜环境中原位测量单个生长和退火的Ni纳米线的电导率。在低电流密度下，退火纳米线的电导率估计已经上升了约2倍以上的生长纳米线。我们将这种增加至少部分归因于观察到的晶粒生长。退火的纳米线随后经受增加的电流密度。高于120 kA mm-2，纳米线电阻开始上升。在450 kA mm-2时，纳米线熔化，电流停止。
The influence of annealing on the microstructure and the electrical properties of cylindrical nickel-based nanowires has been investigated. Nanowires of nickel of nominally 200 nm diameter and of permalloy (Py) of nominally 70 nm were fabricated by electrochemical deposition into nanoporous templates of polycarbonate and anodic alumina, respectively. Characterization was carried out on as-grown nanowires and nanowires heat treated at 650°C. Transmission electron microscopy and diffraction imaging of as-grown and annealed nanowires showed temperature-correlated grain growth of an initially nano-crystalline structure with ≤8 nm (Ni) and ≤20 nm (Py) grains towards coarser poly-crystallinity with grain sizes up to about 160 nm (Ni) and 70 nm (Py), latter being limited by the nanowire width. The electrical conductivity of individual as-grown and annealed Ni nanowires was measured in situ within a scanning electron microscope environment. At low current densities, the conductivity of annealed nanowires was estimated to have risen by a factor of about two over as-grown nanowires. We attribute this increase, at least in part, to the observed grain growth. The annealed nanowire was subsequently subjected to increasing current densities. Above 120 kA mm-2 the nanowire resistance started to rise. At 450 kA mm-2 the nanowire melted and current flow ceased.