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Nanoscale Characterization Facility Penn Engineering
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General Information
Electron Microscopy
Focused Ion Beam
Atomic Force Microscopy
Ion Scattering
  General Morphology

Structural Studies

Compositional Analysis

Surface Studies

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Compositional Analysis
Z-Constrast with High Angle Annular Dark-Field STEM
Scanning transmission electron microscopy (STEM) images of a Zn-containing polymer, acquired on the JEOL 2010F STEM. The images show numerous Zn-rich domains approximately 2.5 nm in diameter. These aggregates enhance the physical properties of the material.

The image in (a) was acquired in bright field STEM, in which the electron density difference between Zn-rich domains and the matrix polymer serves as the contrast mechanism. The aggregates appear dark, without the need for chemical staining which may alter the size of the features.

The image in (b) was acquired in high-angle annular dark field STEM, in which the high atomic number of the Zn-rich domains serves as the contrast mechanism. The aggregates appear bright, confirming that they contain high-atomic-number Zn atoms. Complete correspondence of the features in (a) and (b) is indicated by the circles.

Laurer, J.H.; Winey, K.I. Macromolecules 31(25), 9106-9108, 1998.


Nanoscale Characterization Facility
University of Pennsylvania / 3231 Walnut Street / Philadelphia PA 19104 / / 215.898.8718
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