Issue |
Microsc. Microanal. Microstruct.
Volume 6, Number 1, February 1995
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Page(s) | 79 - 88 | |
DOI | https://doi.org/10.1051/mmm:1995108 |
DOI: 10.1051/mmm:1995108
Characterization of Double Structure Tabular Microcrystals of Silver Halide Emulsions by Means of Electron Energy-Loss Spectroscopy, Zero-Loss Electron Spectroscopic Imaging and Energy-dispersive X-ray Microanalysis
Vladimir Oleshko1, Renaat Gijbels1, Willem Jacob2, Frank Lakiere2, André Van Dele2, Eugeny Silaev3 et Lilia Kaplun31 Department of Chemistry, University of Antwerp (UIA), B-2610 Wilrijk-Antwerpen, Belgium
2 Department of Medicine, University of Antwerp (UIA), B-2610 Wilrijk-Antwerpen, Belgium
3 Research Institute for the Photographic Industry, 125167 Moscow, Russia
Abstract
Electron energy-loss spectroscopy (EELS) and zero-loss
electron spectroscopic imaging (ZLESI) in conjunction with spot
energy-dispersive X-ray microanalysis (EDX) were applied to
the structural and chemical characterization of practical emulsion
core (AgBr)-shell
tabular microcrystals). The samples were cryocooled to minimize
damage under the electron beam. Recorded energy-loss spectra
of the crystals in the initial state and after a 2-minute development
contained several low intensity bands, which were tentatively
assigned to silver and halides, as well as bulk, surface and
defect plasmons and interband transitions. Spatially resolved
energy-loss spectra of silver specks on extractive carbon replicas
of silver halide grains showed the presence of the delayed Ag
-edge at 400 eV. Results of EELS-microanalysis
have been confirmed by EDX spot analysis of the same emulsion
samples. The improved contrast in the ZLESI mode enabled the
detection of dislocation grid and stacking faults on the tabular
grains as well as the visualization of the morphology and defect
structure of silver filaments formed during development of
microcrystals.
Zero-loss filtering was also used to obtain high-resolution
point diffraction patterns of the crystals with low background,
containing extra reflections at commensurate positions in between
the Bragg reflections probably due to a number of defects in
the shell region.
7920K - Other electron surface impact phenomena.
8270K - Emulsions and suspensions.
6180M - Channelling, blocking and energy loss of particles.
8280P - Electron spectroscopy for chemical analysis photoelectron, Auger spectroscopy, etc..
8280D - Electromagnetic radiation spectrometry chemical analysis.
7320M - Collective excitations surface states.
7145G - Exchange, correlation, dielectric and magnetic functions, plasmons.
6170P - Stacking faults, stacking fault tetrahedra and other planar or extended defects.
7155H - Impurity and defect levels in other nonmetals.
6170J - Etch pits, decoration, transmission electron microscopy and other direct observations of dislocations.
Key words
defect states -- dislocation structure -- electron energy loss spectra -- electron spectroscopy -- microemulsions -- plasmons -- silver compounds -- spectrochemical analysis -- stacking faults -- surface plasmons -- X ray chemical analysis -- X ray microscopy -- double structure tabular microcrystals -- emulsions -- electron energy loss spectroscopy -- zero loss electron spectroscopic imaging -- energy dispersive X ray microanalysis -- EELS -- AgBr sub 1 x I sub x tabular microcrystals -- low intensity bands -- bulk plasmons -- surface plasmons -- defect plasmons -- interband transitions -- EDX spot analysis -- dislocation grid faults -- stacking faults -- tabular grains -- morphology -- zero loss filtering -- high resolution point diffraction patterns -- commensurate positions -- Bragg reflections -- shell region -- AgBrI
© EDP Sciences 1995