TY - JOUR
T1 - Chemical composition dispersion in bi-metallic nanoparticles
T2 - Semi-automated analysis using HAADF-STEM
AU - Epicier, T.
AU - Sato, K.
AU - Tournus, F.
AU - Konno, T.
PY - 2012/9
Y1 - 2012/9
N2 - We present a method using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) to determine the chemical composition of bi-metallic nanoparticles. This method, which can be applied in a semi-automated way, allows large scale analysis with a statistical number of particles (several hundreds) in a short time. Once a calibration curve has been obtained, e.g., using energy-dispersive X-ray spectroscopy (EDX) measurements on a few particles, the HAADF integrated intensity of each particle can indeed be directly related to its chemical composition. After a theoretical description, this approach is applied to the case of iron-palladium nanoparticles (expected to be nearly stoichiometric) with a mean size of 8.3 nm. It will be shown that an accurate chemical composition histogram is obtained, i.e., the Fe content has been determined to be 49.0 at.% with a dispersion of 10.4 %. HAADF-STEM analysis represents a powerful alternative to fastidious single particle EDX measurements, for the compositional dispersion in alloy nanoparticles.
AB - We present a method using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) to determine the chemical composition of bi-metallic nanoparticles. This method, which can be applied in a semi-automated way, allows large scale analysis with a statistical number of particles (several hundreds) in a short time. Once a calibration curve has been obtained, e.g., using energy-dispersive X-ray spectroscopy (EDX) measurements on a few particles, the HAADF integrated intensity of each particle can indeed be directly related to its chemical composition. After a theoretical description, this approach is applied to the case of iron-palladium nanoparticles (expected to be nearly stoichiometric) with a mean size of 8.3 nm. It will be shown that an accurate chemical composition histogram is obtained, i.e., the Fe content has been determined to be 49.0 at.% with a dispersion of 10.4 %. HAADF-STEM analysis represents a powerful alternative to fastidious single particle EDX measurements, for the compositional dispersion in alloy nanoparticles.
KW - Bi-metallic nanoparticles
KW - Chemical composition dispersion
KW - Scanning TEM
KW - STEM-HAADF
KW - Transmission electron microscopy
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U2 - 10.1007/s11051-012-1106-z
DO - 10.1007/s11051-012-1106-z
M3 - Article
AN - SCOPUS:84864927254
SN - 1388-0764
VL - 14
JO - Journal of Nanoparticle Research
JF - Journal of Nanoparticle Research
IS - 9
M1 - 1106
ER -