MicroscopyEducation
advanced materials and nanomaterials in the medical field. alignment and atomic resolution imaging to be carried out on a
Routine microscopy at intermediate magnifications can often single specimen that is readily available. Our biggest success—a
be achieved with little understanding of the instrument, but student who was spending half a day aligning the microscope
analysis of nanomaterials requires pushing the operational and was still not confident of his alignment—was aligning the
limits of the microscope. To work at or near the instrument’s 3010 within 10 minutes when he finished the course. Students
resolution specification requires a better understanding of basic are introduced to bright-field and dark-field imaging in the
principles and practices, and this is what we try to provide. “image formation” and the “alignment and operation” modules
The course is taught at the College of Microscopy [1], the and to electron diffraction in the “EELS and diffraction”
newest branch of The McCrone Group in Westmont, Illinois. module.
This is a state-of-the-art teaching facility for all forms of In the “Introduction to AEM: XEDS Analysis” lecture,
microscopy. The laboratory sessions utilize the JEOL JEM-3010 we cover the theory and pitfalls of XEDS analysis, including
TEM in the McCrone Associates consulting laboratory adjacent X-ray generation, detector design, microscope evaluation
to the College. This JEOL JEM-3010 is ideally configured to using the NiOX test specimen, spectral artifacts, specimen
teach this course. It has a STEM unit, several different CCD thickness considerations, and why we should question auto-ID
imaging cameras, an Oxford XEDS system, and a Gatan and semi-quantitative results. In the laboratory sessions, we
Imaging Filter that can be used for EELS spectroscopy, as show some of the pitfalls in setting up the microscope, such as
well as energy-filtered imaging. The standard monitors on the specimen tilt, effect of apertures, and sources of uncollimated
computers are replaced by large LCD panels to give everyone radiation. The “NiOX test specimen” [3] is used to show
an unrestricted view of microscope operations. The class size collection of X-rays, shadowing, hole count, and K-to-L
is limited to no more than six students to ensure that everyone ratio. This specimen is also used for the electron diffraction
gets adequate hands-on time and to avoid crowding in the lab—the introduction of standard specimens for calibration
laboratory. and checking performance is stressed during the course. The
The course runs for three days with increasing amounts student goes away with a better appreciation of the power of the
of hands-on time each day. Laboratory sessions are planned TEM, how easy it can be to produce good quality results, and
to provide practical experience in the topics covered in the the value of practice and experience.
preceding lectures. For example, in the “TEM Alignment and
Operation” lecture, we cover enough electron optics (e.g., Student Feedback
how alignment coils work, features of electromagnetic lenses, We have run the course five times so far, and all students
and stigmators) for the students to understand the principles are required to fill in a survey before they are given their
of alignment and their impact on imaging. In the associated International Association for Continuing Education and
laboratory sessions, the students are shown and given Training (IACET) CEU certificate. Typically they believe that
experience with alignment so they know what to look for and the course objectives were understood and met and that the
what effect poor alignment has on imaging (Figure 3). We use course is applicable to their current and future work. They like
the “combined test specimen” [2] for this lab because it allows how the material is organized and the fact that it is a practical,
A B
Figure 3: Examples of the effect of poor (A) and good (B) alignment on the quality of the best image obtained from graphite (JEOL JEM-3010, 300kV).
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www.microscopy-today.com • 2009 September
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