On the imaging of Pt atoms in zeolite frameworks

S. B. Rice, J. Y. Koo, M. M. Disko, Michael Treacy

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

We compare the relative merits of high-resolution bright-field imaging in the TEM and high-angle annular-dark-field imaging (Z-contrast) in the STEM, for the detection and measurement of small ( <1 nm) noble-metal clusters in zeolites. Pt in K-zeolite L is used as an example system. It is confirmed that high-resolution bright-field imaging is better suited for resolving the zeolite framework. However, even with contrast enhancements gained from image-processing techniques, such as Fourier-filtering, bright-field images are ineffective for detecting clusters containing fewer than ∼ 20 Pt atoms in supports thicker than ∼ 10 nm. This is attributed mainly to ambiguous phase contrast speckle patterns associated with beam-damaged regions of the zeolite framework. Z-contrast images obtained with a STEM high-angle annular detector using a ∼ 0.2 nm probe are shown to be capable of detecting single Pt atoms against a ∼ 20 nm thick zeolite support. However, the precision with which atomic-sized clusters can be located relative to the unit cell is limited by the beam-damage-induced distortion of the zeolite framework.

Original languageEnglish (US)
Pages (from-to)108-118
Number of pages11
JournalUltramicroscopy
Volume34
Issue number1-2
DOIs
StatePublished - 1990
Externally publishedYes

Fingerprint

Zeolites
Imaging techniques
Atoms
atomic clusters
high resolution
speckle patterns
phase contrast
image contrast
metal clusters
noble metals
zeolites
atoms
image processing
Precious metals
Speckle
damage
transmission electron microscopy
augmentation
probes
detectors

ASJC Scopus subject areas

  • Materials Science(all)
  • Instrumentation

Cite this

On the imaging of Pt atoms in zeolite frameworks. / Rice, S. B.; Koo, J. Y.; Disko, M. M.; Treacy, Michael.

In: Ultramicroscopy, Vol. 34, No. 1-2, 1990, p. 108-118.

Research output: Contribution to journalArticle

Rice, S. B. ; Koo, J. Y. ; Disko, M. M. ; Treacy, Michael. / On the imaging of Pt atoms in zeolite frameworks. In: Ultramicroscopy. 1990 ; Vol. 34, No. 1-2. pp. 108-118.
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