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Minimizing sample evaporation in the environmental scanning electron microscope
Author(s) -
CAMERON R. E.,
DONALD A. M.
Publication year - 1994
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1994.tb03445.x
Subject(s) - environmental scanning electron microscope , evaporation , condensation , scanning electron microscope , sample (material) , micrograph , microscope , electron microscope , sample preparation , analytical chemistry (journal) , materials science , chemistry , optics , composite material , chromatography , thermodynamics , physics
Summary The ElectroScan environmental scanning electron microscope (ESEM) enables wet samples to be observed by eliminating air but allowing water vapour into the sample chamber. However, evaporation from, and condensation on, the sample may occur during the pumpdown sequence used to reach this state, which means that the sample may not be in its natural state when viewed if due care is not taken. In this paper, the pumping system of the ESEM is described mathematically and expressions are derived for the evaporation and condensation. This treatment is then used to calculate the optimum pumpdown sequence. The importance of using the optimized procedure is illustrated by micrographs of fat emulsions.