Formation mechanisms of dendrite structures have been extensively explored theoretically, and many theoretical predictions have been validated for micro- or macroscale dendrites. However, it is challenging to determine whether classical dendrite growth theories are applicable at the nanoscale due to the lack of detailed information on the nanodendrite growth dynamics. Here, we study iron oxide nanodendrite formation using liquid cell transmission electron microscopy (TEM). We observe “seaweed”-like iron oxide nanodendrites growing predominantly in two dimensions on the membrane of a liquid cell. By tracking the trajectories of their morphology development with high spatial and temporal resolution, it is possible to explore the relationship between the tip curvature and growth rate, tip splitting mechanisms, and the effects of precursor diffusion and depletion on the morphology evolution. We show that the growth of iron oxide nanodendrites is remarkably consistent with the existing theoretical predictions on dendritic morphology evolution during growth, despite occurring at the nanoscale.

中文翻译：

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通过原位液体细胞电子显微镜揭示溶液生长中纳米级枝晶形成的动力学。

从理论上对树突结构的形成机理进行了广泛的探索，并且对微观或宏观树突的许多理论预测都得到了验证。但是，由于缺乏有关纳米树枝状晶体生长动力学的详细信息，因此确定经典的树枝状晶体生长理论是否适用于纳米规模具有挑战性。在这里，我们使用液体细胞透射电子显微镜（TEM）研究了氧化铁纳米枝晶的形成。我们观察到“海藻”状的氧化铁纳米树突主要在二维的液体细胞膜上生长。通过以高时空分辨率跟踪其形态发展的轨迹，可以探索尖端曲率与生长速率，尖端分裂机制，以及前驱物扩散和耗尽对形态演化的影响。我们表明，尽管在纳米级发生，但氧化铁纳米树枝状晶体的生长与生长期间树突形态演变的现有理论预测非常一致。