For
qualitative analysis, this should be defined as the minimum distance of two points (areas) on the specimen
corresponding to signal levels of 16 and 84%. For electron signals originating from
top surface layers like
secondary or
Auger electrons and secondary ions the lateral resolution for qualitative purposes corresponds to
the
beam diameter. For signals originating in a greater depth of the sample (
back scattered electrons, X-rays) the lateral resolution is worse than the corresponding value of the beam
diameter due to the
diffusion of the
primary electrons. The lateral resolution may be determined exactly with a sandwich specimen or a sharp
edge specimen, or approximately with a specimen showing a regular microstructure of
known dimensions. Recommended abbreviation: Lat. Res. (qualitative); unit:
; range:
or
.
For
quantitative analysis, this should be defined as the minimum distance of two points (areas) on the specimen
corresponding to signal ratios of
. This condition assures that the value for the lateral resolution defines the diameter
of the analytical area which yields the total analytical signal. Due to the effect
of electron
diffusion in a solid and '
tail effects' in ion beam analysis the quantitative lateral resolution is significantly larger
than the beam diameter. Recommended abbreviation: Lat. Res. (quantitative); unit:
; range:
or
.
Source:
PAC, 1983, 55, 2023
(Nomenclature, symbols and units recommended for in situ microanalysis (Provisional))
on page 2027
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
