thickness and resolution

[Philip Koeck]

Dear list members,

in the book 'Polymer Microscopy' by Sawyer and Grubb I read about  a rule of thumb relating
attainable resolution to the specimen thickness (about 1/15 of the thickness for carbon specimens
imaged with 100 keV electrons).
The authors refer to the second edition of Reimer but I can't find this statement in the fourth edition
anymore.

How seriously should this rule of thumb be taken for TEM phase contrast imaging?
Does anybody know of a publication giving estimates for different electron energies and specimen
thicknesses?

On pages 190ff in Reimer 4th ed. I found a discussion of the 'top-bottom effect' in STEM with
some references to publications on similar effects in TEM and energy-filtered TEM.
Would the resolution in a TEM phase contrast image depend on whether the specimen
is above or beneath the support film?

Thankful for any comments and references,

Philip

Philip Koeck
Södertörns Högskola and
Karolinska Institutet
Dept. of Bioscience at Novum
S-14157 Huddinge
Sweden
phone: +46-8-6089186
fax: +46-8-6089290
http://www.biosci.ki.se/em

The phrase 'We have always done things this way.'
is as much a reason to change as a reason not to.
- Dartwill Aquila
_______________________________________


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