TY - JOUR
T1 - Z contrast of platinum and palladium catalysts
AU - Treacy, M. M.J.
AU - Howie, A.
AU - Wilson, C. J.
N1 - Funding Information:
The authors would like to thank Dr. L. 31. Brown for his encouragement and for many useful discussions. The authors are grateful to Johnson Matthey Chemicals Ltd. for supplying specimens and to Dr. D. E. Webster and Mr. I. L. Dodgson for useful discussions, and are also grateful to A. B. Mistry for supplying the a(0) data relevant for fig. 2. Financial support from the Science Research Council for the electron microscopy work and for a CASE research studentship (JIMJT) is gratefully acknowledged.
PY - 1978/11
Y1 - 1978/11
N2 - The usefulness of Crewe's Z-contrast technique for the study of small catalyst particles in the scanning transmission electron microscope is investigated and discussed. By forming suitable combinations of the annular dark-field and energy-loss signals, structural details in platinum particles as small as 2 nm may be imaged, and clusters of image size approaching the probe dimensions (0·5 nm), not visible in the bright-field images, may be detected. In the case of crystalline supports, about 10% of the particles are obscured by strong diffraction contrast in the substrate, although it is found that contrast variations arising from thickness variations in the substrate are suppressed in the energy-loss signal. Particle sizes in the various signals employed are compared.
AB - The usefulness of Crewe's Z-contrast technique for the study of small catalyst particles in the scanning transmission electron microscope is investigated and discussed. By forming suitable combinations of the annular dark-field and energy-loss signals, structural details in platinum particles as small as 2 nm may be imaged, and clusters of image size approaching the probe dimensions (0·5 nm), not visible in the bright-field images, may be detected. In the case of crystalline supports, about 10% of the particles are obscured by strong diffraction contrast in the substrate, although it is found that contrast variations arising from thickness variations in the substrate are suppressed in the energy-loss signal. Particle sizes in the various signals employed are compared.
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U2 - 10.1080/01418617808239255
DO - 10.1080/01418617808239255
M3 - Article
AN - SCOPUS:0018032284
SN - 0141-8610
VL - 38
SP - 569
EP - 585
JO - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
JF - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
IS - 5
ER -