SCANNING ELECTRON MICROSCOPY
The LEO 982 Field emission scanning electron microscope (FE-SEM, LEO Electron Microsopy, Inc. One Zeiss Drive, Thornwood, NY 10594)) provides a means to achieve ultra high
resolution images in the secondary emissive mode. The instrument is, in effect, an analytical work
station since it combines secondary imaging capabilities with backscatter electron imaging useful
for discriminating elements by atomic number contrast. These imaging modes combined with an Oxford (Oxford Instruments, Inc., 130a Baker Ave. Ext., Concord, MA 01742)
energy dispersive X-ray analyzer allow for positive identification of elements by spectral analysis,
mapping of element distribution, combined with qualitative and quantitative analysis of element
concentration. Particle sizing, counting, and chemical typing can be achieved using image
processing software on the X-ray analyzer using image processing software on the X-ray
analyzer.
A
new addition is the
Gatan Alto 2500 Cryostage and cryoprep chamber (Gatan UK, Ferrymills 3, Osney Mead, Oxford, OX2 0ES, UK). With the attached vacuum chamber, the sample can be rapidly frozen in LN slush and transferred to the cryoprep chamber. It is kept frozen and can be fractured, sublimated and coated in the chamber, then moved to the cryostage within the SEM and kept frozen while viewed. Several mounts are available to accomodate a variety of specimens.
