@article{3ef9620d6cce46038ecce951d48b03b1,
title = "Dynamics of Transformation from Platinum Icosahedral Nanoparticles to Larger FCC Crystal at Millisecond Time Resolution",
abstract = "Atomic motion at grain boundaries is essential to microstructure development, growth and stability of catalysts and other nanostructured materials. However, boundary atomic motion is often too fast to observe in a conventional transmission electron microscope (TEM) and too slow for ultrafast electron microscopy. Here, we report on the entire transformation process of strained Pt icosahedral nanoparticles (ICNPs) into larger FCC crystals, captured at 2.5 ms time resolution using a fast electron camera. Results show slow diffusive dislocation motion at nm/s inside ICNPs and fast surface transformation at μm/s. By characterizing nanoparticle strain, we show that the fast transformation is driven by inhomogeneous surface stress. And interaction with pre-existing defects led to the slowdown of the transformation front inside the nanoparticles. Particle coalescence, assisted by oxygen-induced surface migration at T ≥ 300 °C, also played a critical role. Thus by studying transformation in the Pt ICNPs at high time and spatial resolution, we obtain critical insights into the transformation mechanisms in strained Pt nanoparticles.",
author = "Wenpei Gao and Jianbo Wu and Aram Yoon and Ping Lu and Liang Qi and Jianguo Wen and Miller, {Dean J.} and Mabon, {James C.} and Wilson, {William L.} and Hong Yang and Zuo, {Jian Min}",
note = "Funding Information: This work was supported by NSF DMR-1410596 (WG, AY and JMZ), DOE BES DEFG02-01ER45923 (JBW and JMZ), NSF CHE-1213926 (JBW and HY), and Shen Fellowship from Department of Chemical and Biomolecular Engineering at UIUC (JBW and HY). The development of environmental TEM with fast imaging capability was supported by NSF MRI-1229454 (JMZ and WLW). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. The transmission electron microscopy was partially performed at the Electron Microscopy Center in the Center for Nanoscale Materials at ANL, a DOE-BES Facility, supported under Contract No. DE-AC02-06CH11357 by University of Chicago Argonne, LLC. We thank the technical help from Drs Hyuk Park of University of Illinois, Xiaofeng Zhang of Hitachi and Cory Czarnik of Gatan Inc. Funding Information: This work was supported by NSF DMR-1410596 (WG, AY and JMZ), DOE BES DEFG02-01ER45923 (JBW and JMZ), NSF CHE-1213926 (JBW and HY), and Shen Fellowship from Department of Chemical and Biomolecular Engineering at UIUC (JBW and HY). The development of environmental TEM with fast imaging capability was supported by NSF MRI-1229454 (JMZ and WLW). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy{\textquoteright}s National Nuclear Security Administration under contract DE-AC04-94AL85000. The transmission electron microscopy was partially performed at the Electron Microscopy Center in the Center for Nanoscale Materials at ANL, a DOE-BES Facility, supported under Contract No. DE-AC02-06CH11357 by University of Chicago Argonne, LLC. We thank the technical help from Drs Hyuk Park of University of Illinois, Xiaofeng Zhang of Hitachi and Cory Czarnik of Gatan Inc. Publisher Copyright: {\textcopyright} 2017 The Author(s).",
year = "2017",
month = dec,
day = "1",
doi = "10.1038/s41598-017-16900-6",
language = "English (US)",
volume = "7",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",
}