论文标题
电气移民对纳米线形态不稳定性发作的影响
Effect of Electromigration on Onset of Morphological Instability of a Nanowire
论文作者
论文摘要
固体圆柱纳米线容易受到雷利 - 普拉托型形态不稳定性的影响。不稳定性导致电线破裂，然后形成球形纳米颗粒的链阵列。在本文中，考虑了沿纳米线轴的施加电场中纳米材料上形态不稳定性的基础模型。获得90度接触角的精确分析溶液，并假设轴对称扰动对于独立的线。后一种解决方案扩展了1965年的尼科尔和穆林斯，没有电迁移效应（F.A. Nichols和W.W. Mullins，Trans。Metall。Soc。Aime233，1840-1848（1965））。对于一般接触角，中性稳定性是数值确定的。结果表明，更强的施加电场（更强的电流）会导致较大的不稳定性增长率和最危险的不稳定波长的降低。在实验中，后者有望产生更致密的纳米颗粒阵列。还注意到，基板上的电线晶体学方向对更强的电场中的稳定性有更大的影响，并且简单地切换了电触点的极性，即，施加电场方向的逆转可能会抑制不稳定性的发展，从而防止电线破裂。获得了电线稳定所需的电场的临界值。
Solid cylindrical nanowires are vulnerable to a Rayleigh-Plateau-type morphological instability. The instability results in a wire breakup, followed by formation of a chain array of spherical nanoparticles. In this paper, a base model of a morphological instability of a nanowire on a substrate in the applied electric field directed along a nanowire axis is considered. Exact analytical solution is obtained for 90 degrees contact angle and, assuming axisymmetric perturbations, for a free-standing wire. The latter solution extends the 1965 result by Nichols and Mullins without electromigration effect (F.A. Nichols and W.W. Mullins, Trans. Metall. Soc. AIME 233, 1840-1848 (1965)). For general contact angles the neutral stability is determined numerically. It is shown that a stronger applied electric field (a stronger current) results in a larger instability growth rate and a decrease of the most dangerous unstable wavelength; in experiment, the latter is expected to yield more dense chain array of nanoparticles. Also it is noted that a wire crystallographic orientation on a substrate has larger impact on stability in a stronger electric field and that a simple switching of the polarity of electrical contacts, i.e. the reversal of the direction of the applied electric field, may suppress the instability development and thus a wire breakup would be prevented. A critical value of the electric field that is required for such wire stabilization is obtained.
