Abstract Additives and impurities often strongly influence the growth and shape of crystals, sometimes in an unexpected way. Heteroepitaxial growth of 3D guest crystals on different substrate crystals leads to a variety of surface patterns as has commonly been reported. Homoepitaxial growth, on the other hand, generally proceeds by layer by layer growth and leads to flat surfaces with steps. In our study we found that applying a droplet of ethanol with traces of triamide additive on a (0 0 1) NaCl substrate surface results in a 3D pseudo-homoepitaxial pattern comprising of ultrathin NaCl needles ordered in a “Mondriaan-like” arrangement. This is a consequence of small amounts of water in the ethanol, absorbed from the ambient, dissolving NaCl from the substrate, followed by poisoning the substrate surface by additive adsorption, which inhibits NaCl regrowth later on. At the last phase of droplet evaporation the NaCl supersaturation becomes very high and epitaxial crystal needles develop, starting from several oriented 3D nuclei on the poisoned substrate surface. This leads to a network of epitaxial NaCl needles each pointing toward one of the four perpendicular 〈1 0 0〉 directions on the (0 0 1) NaCl substrate. This peculiar phenomenon of 3D pseudo-homoepitaxy results from a subtle interplay between crystal dissolution, additive blocking and final growth at high supersaturation.

中文翻译：

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纳米针在 NaCl 晶体上的添加剂诱导假同质外延

摘要 添加剂和杂质通常会强烈影响晶体的生长和形状，有时会以意想不到的方式。3D 客体晶体在不同衬底晶体上的异质外延生长会导致各种表面图案，正如通常报道的那样。另一方面，同质外延生长通常逐层生长并导致平坦的表面具有台阶。在我们的研究中，我们发现在 (0 0 1) NaCl 基材表面上应用一滴带有痕量三酰胺添加剂的乙醇会产生 3D 伪同质外延图案，该图案由以“蒙德里安式”排列排列的超薄 NaCl 针组成。这是由于乙醇中的少量水从环境中吸收，从基材中溶解 NaCl，然后通过添加剂吸附使基材表面中毒，这会在以后抑制 NaCl 的再生。在液滴蒸发的最后阶段，NaCl 过饱和度变得非常高，并且从中毒基板表面上的几个定向 3D 核开始形成外延晶针。这导致了外延 NaCl 针的网络，每个针指向 (0 0 1) NaCl 基板上的四个垂直<1 0 0> 方向之一。3D 伪同质外延的这种特殊现象是晶体溶解、添加剂阻塞和高过饱和度下的最终生长之间微妙的相互作用造成的。这导致了外延 NaCl 针的网络，每个针指向 (0 0 1) NaCl 基板上的四个垂直<1 0 0> 方向之一。3D 伪同质外延的这种特殊现象是晶体溶解、添加剂阻塞和高过饱和度下的最终生长之间微妙的相互作用造成的。这导致了外延 NaCl 针的网络，每个针指向 (0 0 1) NaCl 基板上的四个垂直<1 0 0> 方向之一。3D 伪同质外延的这种特殊现象是晶体溶解、添加剂阻塞和高过饱和度下的最终生长之间微妙的相互作用造成的。