Mariano Ruperto G, Yau Allison, McKeown Joseph T, Kumar Mukul, Kanan Matthew W
Department of Chemistry, Stanford University, Stanford, California 94305, United States.
Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States.
ACS Omega. 2020 Feb 7;5(6):2791-2799. doi: 10.1021/acsomega.9b03505. eCollection 2020 Feb 18.
Investigating how grain structure affects the functional properties of nanoparticles requires a robust method for nanoscale grain mapping. In this study, we directly compare the grain mapping ability of transmission Kikuchi diffraction (TKD) in a scanning electron microscope to automated crystal orientation mapping (ACOM) in a transmission electron microscope across multiple nanoparticle materials. Analysis of well-defined Au, ZnO, and ZnSe nanoparticles showed that the grain orientations and GB geometries obtained by TKD are accurate and match those obtained by ACOM. For more complex polycrystalline Cu nanostructures, TKD provided an interpretable grain map whereas ACOM, with or without precession electron diffraction, yielded speckled, uninterpretable maps with orientation errors. Acquisition times for TKD were generally shorter than those for ACOM. Our results validate the use of TKD for characterizing grain orientation and grain boundary distributions in nanoparticles, providing a framework for the broader exploration of how microstructure influences nanoparticle properties.
研究晶粒结构如何影响纳米颗粒的功能特性需要一种用于纳米级晶粒测绘的可靠方法。在本研究中，我们直接比较了扫描电子显微镜中的透射菊池衍射（TKD）与透射电子显微镜中的自动晶体取向映射（ACOM）在多种纳米颗粒材料上的晶粒测绘能力。对明确的金、氧化锌和硒化锌纳米颗粒的分析表明，通过TKD获得的晶粒取向和晶界几何形状是准确的，并且与通过ACOM获得的结果相匹配。对于更复杂的多晶铜纳米结构，TKD提供了一个可解释的晶粒图，而ACOM无论有无进动电子衍射，都产生了有斑点的、无法解释的图，且存在取向误差。TKD的采集时间通常比ACOM短。我们的结果验证了TKD用于表征纳米颗粒中晶粒取向和晶界分布的有效性，为更广泛地探索微观结构如何影响纳米颗粒特性提供了一个框架。
