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Imaging faces of shadowed magnetite (Fe 3 O 4 ) crystals from magnetotactic bacteria with energy‐filtering transmission electron microscopy
Author(s) -
Lins Ulysses,
Kachar Bechara,
Farina Marcos
Publication year - 1999
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/(sici)1097-0029(19990815/01)46:4/5<319::aid-jemt9>3.0.co;2-n
Subject(s) - magnetotactic bacteria , transmission electron microscopy , scanning transmission electron microscopy , magnetite , electron microscope , materials science , microscopy , energy filtered transmission electron microscopy , scanning confocal electron microscopy , optics , conventional transmission electron microscope , dark field microscopy , scanning electron microscope , nanotechnology , physics , metallurgy
We used energy‐filtering transmission electron microscopy to image magnetite crystals isolated from uncultured magnetotactic bacteria. These magnetite crystals were shadowed in high vacuum with platinum at 45°. The shadowed crystals were observed in a Zeiss (Thornwood, NY) CEM902 transmission electron microscope. Imaging shadowed crystals with inelastically scattered electrons provided information of the decoration pattern of small platinum particles over crystal surfaces, and thus information on surface characteristics of crystals. Results were comparable to those obtained from scanning electron microscopy using a field emitter gun. Electron energy loss spectra of the crystals as well as of the supporting film were recorded to evaluate variations of image contrast with energy losses. Results indicated that the contrast is attenuated with inelastic imaging and that the effect of contrast tuning caused a contrast inversion at a given point between 100 and 150 eV. We believe this approach can be useful for studying multilayered materials by transmission electron microscopy. Microsc. Res. Tech. 46:319–324, 1999. © 1999 Wiley‐Liss, Inc.