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.
Hauwiller, M. R., Zhang, X., Liang, W.-I., Chiu, C.-H., Zhang, Q., Zheng, W., … Zheng, H. (2018). Dynamics of Nanoscale Dendrite Formation in Solution Growth Revealed Through in Situ Liquid Cell Electron Microscopy. Nano Letters, 18(10), 6427–6433. doi:10.1021/acs.nanolett.8b02819
This work was funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-05-CH11231 within the insitu TEM program (KC22ZH). Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy, under Contract No. DE-AC02-05CH11231. We acknowledge Gatan Inc. for the advanced K2 IS camera. M.R.H. acknowledges the support of a KAUST CRG grant at UC Berkeley. C.-H.C. was funded by Ministry of Science and Technology (MOST) in Taiwan (Grant 103-2917-I-009-185). W.-I.L. was partially funded by MOST in Taiwan (NSC 102-2119-I-009-502). X.Z. acknowledges the support of the National Basic Research Program of China (2013CB632101) and China Scholarship Council under Grant No. 201406190080. The authors declare no competing financial interests.