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Dynamics and control of gold-encapped gallium arsenide nanowires imaged by 4D electron microscopy

Chen, Bin and Fu, Xuewen and Tang, Jau and Lysevych, Mykhaylo and Tan, Hark Hoe and Jagadish, Chennupati and Zewail, Ahmed H. (2017) Dynamics and control of gold-encapped gallium arsenide nanowires imaged by 4D electron microscopy. Proceedings of the National Academy of Sciences of the United States of America, 114 (49). pp. 12876-12881. ISSN 0027-8424. PMCID PMC5724258. doi:10.1073/pnas.1708761114.

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Eutectic-related reaction is a special chemical/physical reaction involving multiple phases, solid and liquid. Visualization of a phase reaction of composite nanomaterials with high spatial and temporal resolution provides a key understanding of alloy growth with important industrial applications. However, it has been a rather challenging task. Here, we report the direct imaging and control of the phase reaction dynamics of a single, as-grown free-standing gallium arsenide nanowire encapped with a gold nanoparticle, free from environmental confinement or disturbance, using four-dimensional (4D) electron microscopy. The nondestructive preparation of as-grown free-standing nanowires without supporting films allows us to study their anisotropic properties in their native environment with better statistical character. A laser heating pulse initiates the eutectic-related reaction at a temperature much lower than the melting points of the composite materials, followed by a precisely time-delayed electron pulse to visualize the irreversible transient states of nucleation, growth, and solidification of the complex. Combined with theoretical modeling, useful thermodynamic parameters of the newly formed alloy phases and their crystal structures could be determined. This technique of dynamical control aided by 4D imaging of phase reaction processes on the nanometer-ultrafast time scale opens new venues for engineering various reactions in a wide variety of other systems.

Item Type:Article
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URLURL TypeDescription Information Paper CentralArticle
Fu, Xuewen0000-0001-6116-4680
Tang, Jau0000-0003-2078-1513
Alternate Title:Eutectic dynamics and control of gold-encapped gallium arsenide nanowires imaged by 4D electron microscopy
Additional Information:© 2017 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND). Edited by Charles M. Lieber, Harvard University, Cambridge, MA, and approved October 26, 2017 (received for review May 26, 2017). Published online before print November 20, 2017. We thank J. S. Baskin and J. S. Huang for very helpful discussion. This work was supported by Air Force Office of Scientific Research Grant FA9550-11-1-0055S in the Gordon and Betty Moore Foundation for Physical Biology Center for Ultrafast Science and Technology at California Institute of Technology. M.L., H.H.T., and C.J. thank the Australian Research Council for support and the Australian National Fabrication Facility for access to the epitaxial facilities used in this work. Author contributions: B.C. and A.H.Z. designed research; B.C., X.F., and M.L. performed research; B.C., J.T., and A.H.Z. contributed new reagents/analytic tools; B.C., X.F., J.T., M.L., H.H.T., C.J., and A.H.Z. analyzed data; and B.C., X.F., J.T., M.L., H.H.T., C.J., and A.H.Z. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. This article contains supporting information online at
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-11-1-0055S
Australian Research CouncilUNSPECIFIED
Subject Keywords:phase reaction; Au/GaAs nanowires; structural dynamics; eutectic dynamics; 4D electron microscopy
Issue or Number:49
PubMed Central ID:PMC5724258
Record Number:CaltechAUTHORS:20170605-084009912
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Official Citation:Bin Chen, Xuewen Fu, Jau Tang, Mykhaylo Lysevych, Hark Hoe Tan, Chennupati Jagadish, and Ahmed H. Zewail Dynamics and control of gold-encapped gallium arsenide nanowires imaged by 4D electron microscopy PNAS 2017 114 (49) 12876-12881; published ahead of print November 20, 2017, doi:10.1073/pnas.1708761114
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:77937
Deposited By: Tony Diaz
Deposited On:05 Jun 2017 21:31
Last Modified:21 Mar 2022 16:58

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