electron microscopy
 

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Results obtained on the Beam-Corrected HD 2700 CS

Properties of the microscope

Dedicated scanning transmission electron microscope (STEM)
Cold field emission gun (FEG); acceleration voltage Vacc= 80, 120, 200kV
CEOS corrector system for the probe-forming objective lens

Working modes:
Ultra High Resolution (UHR): beam diameter ≤ 0.1 nm ⇒ resolution < 0.1 nm
High Resolution (HR): beam diameter ca. 0.2 nm

Normal: beam diameter ≥ 0.3 nm

Equipment:
BF and (HA)ADF detectors, secondary electron (SE) detector,
Gatan Orius CCD camera, Gatan EEL spectrometer, EDXS detector (EDAX)

Description of the microscope:
Performance and image analysis of the aberration-corrected Hitachi HD-2700C STEM

H. Inada, L. Wu, J. Wall, D. Su, and Y. Zhu, J. Electron Microsc. 58 (2009) 111–122 DOI

 

Imaging with High Resolution

HAADF-STEM (Z contrast) images of Pt on TiO2 (left) and on C foil (right), respectively. In the right image, isolated bright dots correspond to single Pt atoms. Samples: Makosch, Van Bokhoven (ICB, ETH Zürich).

The structure of Au nanoparticles can be observed in high resolution by phase contrast (PC), Z contrast (ZC), and even by secondary electron (SE) imaging.

Images of ceria nanocrystal along <110> recorded with different detectors: HAADF-STEM (left) and phase contrast mode (center). The contrast in the PC STEM image strongly depends on the focus f as exemplified by the contrast inversion in the images on the right (Δf ≈ 20 nm). Sample: Baudouin, Copéret (LAC, ETH Zürich).

 

Nano analysis by EDXS

(a) SE image of RuO2 nanoparticles on SnO2. (b) EDX spectra of the nanoparticles (area 1) coating the support crystals (area 2) proving the coating of SnO2 by RuO2 nanoparticles. Sample: Mondelli, Pérez-Ramírez (ICB, ETH Zürich).

ZC-STEM image of AuPd nanoparticles on titania (left) and EDXS elemental map of Au (right). Particles with a diameter of around 2 nm are still recognizable in the map. Sample: Marx, Baiker (ICB, ETH Zürich).


Publications

Catalyst Characterization: TEM vs. STEM - Visualizing Pt Nanoparticles Supported on Cerium Oxide
F. Krumeich and E. Müller, Imaging & Microscopy 12 (2) (2010) 24-27

Characterization of Catalysts in an Aberration-Corrected Scanning Transmission Electron Microscope
F. Krumeich, E. Müller, R. A. Wepf, and R. Nesper, J. Phys. Chem C 115 (2011) 1080–1083 DOI

Surface Properties and Morphology of Supported, Colloid-Derived Gold/Palladium Mono- and Bimetallic Nanoparticles
S. Marx, F. Krumeich, and A. Baiker, J. Phys. Chem. C 115 (2011) 8195-8205 DOI

Characterization of AuPd Nanoparticles by Probe-Corrected Scanning Transmission Electron Microscopy and X-Ray Absorption Spectroscopy
F. Krumeich, S. Marx, A. Baiker, and R. Nesper, Z. anorg. allg. Chem. 637 (2011) 875–881 DOI

Phase-Contrast Imaging in Aberration-Corrected Scanning Transmission Electron Microscopy
F. Krumeich, E. Müller, and R. A. Wepf, Micron 2013, 49, 1-14 DOI

 

 

ETH Zürich | ETH chemistry department | ETH inorganic chemistry

modified: 9 January, 2019 by F. Krumeich | © ETH Zürich and the authors