CS-corrected Microscope

Results Obtained on the Beam-Corrected Hitachi HD 2700 CS

Properties of the Microscope

Dedicated scanning transmission electron microscope (STEM)
Cold field emission gun (FEG); acceleration voltage U_acc= 200kV
external page CEOS external page 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, external page Gatan Orius
CCD camera, external page Gatan EEL spectrometer, EDXS detector (external page 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

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

Enlarged view: Gold nanoparticle — 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.

Enlarged view: Ceroxide nanoparticle — 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

Ruthenium nanoparticles — (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).

Enlarged view: Gold-palladium nanoparticles — 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 recognizable in the map. Sample: Marx, Baiker (ICB, ETH Zürich).

Selected Publications

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 2011, 115, 1080–1083 external page 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 2011, 115, 8195-8205 external page 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. 2011, 637, 875–881 external page DOI

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