We report a growth mechanism that produces in-plane $\left[1\overline{1}0\right]$ oriented ErSb nanowires formed during codeposition of $\mathrm{E}{\mathrm{r}}_{0.3}\mathrm{G}{\mathrm{a}}_{0.7}\mathrm{Sb}$ via molecular beam epitaxy (MBE). Nanowires are characterized by in situ scanning tunneling microscopy (STM), as well as ex situ transmission electron microscopy (TEM) and electron channeling contrast imaging. We show that complexes of macrosteps with step heights on the order of 7 nm form during nanowire growth. The macrosteps are shown to be part of the in-plane nanowire growth process and are directly responsible for the observed stratified distribution of in-plane nanowires. TEM indicates that initial growth results in out-of-plane nanowires transitioning to in-plane nanowires after a critical film thickness. A surface energy model is put forward that shows the critical thickness is due to minimization of the $\mathrm{GaSb}\left\{110\right\}$ surfaces formed during out-of-plane nanowire growth. Kinetics of the transition are discussed with respect to observed features in STM, along with the material parameters needed to achieve in-plane nanowire growth.

中文翻译：

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嵌入式面内自组装纳米线形成的机制

我们报告了一种产生面内增长的增长机制 $\left[\mathrm{1个}\overline{\mathrm{1个}}0\right]$ 的共沉积过程中形成的取向的ErSb纳米线 $\mathrm{Ë}{\mathrm{[R}}_{0.3}\mathrm{G}{\mathrm{一种}}_{0.7}锑$通过分子束外延（MBE）。纳米线的特征在于原位扫描隧道显微镜（STM），非原位透射电子显微镜（TEM）和电子通道对比成像。我们显示，在纳米线生长过程中，具有7纳米数量级的台阶高度的宏台阶复合物。宏观步骤显示为平面内纳米线生长过程的一部分，直接负责观察到的平面内纳米线的分层分布。TEM表明，初始生长导致临界膜厚后面外纳米线转变为面内纳米线。提出了一个表面能模型，该模型表明临界厚度是由于最小化$\mathrm{砷化镓}\left\{110\right\}$在平面外纳米线生长期间形成的表面。讨论了转变的动力学，涉及在STM中观察到的特征，以及实现面内纳米线生长所需的材料参数。