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The Philips CM20 transmission electron
microscope has an accelerating voltage of
200 kV and is equipped with a
LaB6 filament and a side-entry
stage. This instrument is particularly
suitable for CTEM (conventional TEM),
including bright-field imaging, dark-field
imaging, and weak-beam dark-field imaging
of defects in crystalline materials. Owing
to the large tilt radius of the goniometer,
this instrument is also well suited for
stereo TEM. Moreover, the CM20 has
versatile capabilities for analytical TEM.
A scanning unit allows scanning a fine
electron probe across the sample, and by
means of corresponding bright-field and
dark-field electron detectors one can
record STEM (scanning TEM) images.
Apart from STEM images, the fine electron
probe is useful for CBED (convergent-beam
electron diffraction studies. For elemental
analysis via XEDS (X-ray energy-dispersive
spectrometry), the CM20 is equipped with a
Noran X-ray detector (HPGe UTW), sensitive
to a broad range of photon energies and
capable of detecting light elements,
including boron, as well as heavy elements.
The system also has a Gatan PEELS
(parallel-acquisition electron energy-loss
spectrometer) for light-element detection
and composition analysis. With this
equipment, the CM20 enables microchemical
and micro-crystallographic analysis at a
spatial resolution down to about 10nm.
Additional features include a special
specimen holder for in-situ heating
and cooling.
This material is based upon
work supported by the National Science
Foundation. Any opinions, findings, and
conclusions or recommendations expressed in
this material are those of the author(s)
and do not necessarily reflect the views of
the National Science Foundation.
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