Peer-Reviewed Journal Details
Mandatory Fields
Nakahara, S; Tanner, DA; Hudson, S; Magner, E; Redington, W; Hodnett, K
2011
Physical Chemistry Chemical Physics
Defocus image contrast in hexagonally-ordered mesoporous material
Published
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Optional Fields
TRANSMISSION ELECTRON-MICROSCOPY MOLECULAR-SIEVES SILICA SBA-15 FILMS TOMOGRAPHY ADSORPTION
13
3
1189
1200
A transmission electron microscope was used to characterize a powder form of hexagonally-ordered mesoporous silica material. The structural symmetry built into this amorphous material allowed one to obtain three characteristic images, i.e. a hexagonal honey-comb structure and wide/narrow parallel lines. These images were found to originate primarily from phase contrast, which changed sensitively with defocusing. To further understand the contrast behaviour of these images, an analytical form of the defocus contrast theory was developed and applied to the simulation of the characteristic wide/narrow parallel line images. The simulation was found to be in good qualitative agreement with experiments, where changes in focus conditions and specimen thickness were predicted to alter the contrast in the resulting parallel-line type images.
1463-9076
10.1039/c0cp01141j
Grant Details