Kinetic pathways of crystallization at the nanoscale
Kinetic pathways of crystallization at the nanoscale
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DOI：
10.1038/s41563-019-0514-1
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发表时间：
2020-04-01
期刊：
影响因子：
41.2
通讯作者：
Chen, Qian
中科院分区：
文献类型：
--
作者：
Ou, Zihao;Wang, Ziwei;Chen, Qian
在从原子尺度到微米尺度的系统中，成核和生长是普遍重要的，因为它们决定了晶体的结构和功能属性。然而，在纳米尺度上，由于解决单个构建块在液体介质中的运动的挑战，结晶的途径在很大程度上尚未被探索。在这里，我们通过在单粒子水平上直接成像分散的金纳米棱镜到超晶格的完整转变来解决这一差距。我们利用低剂量率的液相透射电子显微镜来控制纳米颗粒的相互作用，而不影响它们的运动。结合粒子跟踪和蒙特卡罗模拟，我们揭示了超晶格的位置有序是由取向无序产生的。这种方法允许我们测量诸如线张力和相坐标等参数，绘制涉及致密非晶中间体的非经典成核途径。我们通过不同纳米颗粒的结晶展示了我们方法的多功能性，为更广泛的应用指明了道路。采用低剂量液相透射电子显微镜、粒子跟踪和数值模拟技术，在单粒子水平上表征了金纳米片的结晶动力学和路径。
Nucleation and growth are universally important in systems from the atomic to the micrometre scale as they dictate structural and functional attributes of crystals. However, at the nanoscale, the pathways towards crystallization have been largely unexplored owing to the challenge of resolving the motion of individual building blocks in a liquid medium. Here we address this gap by directly imaging the full transition of dispersed gold nanoprisms to a superlattice at the single-particle level. We utilize liquid-phase transmission electron microscopy at low dose rates to control nanoparticle interactions without affecting their motions. Combining particle tracking with Monte Carlo simulations, we reveal that positional ordering of the superlattice emerges from orientational disorder. This method allows us to measure parameters such as line tension and phase coordinates, charting the nonclassical nucleation pathway involving a dense, amorphous intermediate. We demonstrate the versatility of our approach via crystallization of different nanoparticles, pointing the way to more general applications.Low-dose liquid-phase transmission electron microscopy, particle tracking and numerical simulations are used to characterize the crystallization kinetics and pathways of gold nanoprisms at the single-particle level.