High-resolution HAADF-STEM and Molecular Simulations of Bare and Protected Metal Nanoparticles

S. MEJIA-ROSALES; M. M. MARISCAL; M. J. YACAMÁN

Congreso; ICMAT 2013; 2013

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High-resolution HAADF-STEM and Molecular Simulations of Bare and Protected Metal Nanoparticles Sergio MEJÍA-ROSALES1#+, Marcelo MARISCAL2, Miguel JOSÉ-YACAMÁN3 1Universidad Autonoma de Nuevo Leon, Mexico, 2Mathematics and Physics, Universidad Nacional de Córdoba, Argentina, 3Physics and Astronomy, University of Texas at San Antonio, United States #Corresponding author: sergio.mejiars@uanl.edu.mx +Presenter High resolution electron microscopy imaging is one of the most useful techniques to investigate the structural detail of metal nanoparticles, with sub-Angstrom resolution. In particular, aberration-corrected scanning transmission electron microscopy, when coupled with a high angle annular dark field detector, provides micrographs where the intensity is strongly dependent on the elements present on the specimen, and thus local composition of nanoalloys can be investigated. In this talk we will discuss several theoretical tools used jointly with high resolution electron micrographs, with a particular interest in the aberration-corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), in the study of structural and dynamical properties of metal nanostructures and nanoalloys. We will illustrate how HAADF-STEM images, electron microscopy simulations, and molecular dynamics simulations can be used as complementary techniques to quantitatively measure atomic concentrations and elastic properties, and to generate three-dimensional models of nanoalloys, with a particular emphasis on Pd, Pt, Ag, and Au mono- and bi-metallic nanoparticles. The effect of substrate and organic ligand molecules acting as passivating agents is also discussed.