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Secondary Electron Contrast in Molecular Liquids

Published online by Cambridge University Press:  02 July 2020

B.L. Thiel
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Madingley Road, Cambridge, CB3 OHE, U.K.
D.J. Stokes
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Madingley Road, Cambridge, CB3 OHE, U.K.
A.M. Donald
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Madingley Road, Cambridge, CB3 OHE, U.K.
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Extract

Liquid containing specimens can be stabilized for observation in the Environmental Scanning Electron Microscope (ESEM). It is also possible to examine systems that are primarily liquid, such as colloidal suspensions and gels, or even possess a multi-component liquid microstructure as in emulsions.(l) In order for such investigations to be useful, an understanding of the origins of secondary electron contrast in liquids is necessary. Our aim here is not to produce a complete theory of secondary electron emission in these systems, but to provide general guidelines for discriminating between two liquids based on relative contrast.

Secondary electron emission from a substance is determined by three processes: creation, transport through the material, and escape from the surface.(2) Contrast between two regions will be due to differences in one or more of these processes. Initial generation of secondary electrons is primarily a function of the ionization cross-sections of the substance and its density.

Type
New Trends in Scanning Electron Microscopy and Microanalysis
Copyright
Copyright © Microscopy Society of America

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References

1) Stokes, D.J., Thiel, B.L., and Donald, A.M., elsewhere in these proceedings.Google Scholar

2) Dekker, A., in Solid State Physics, 6 (1955) 251, (Seitz, F. and Turnbull, D. eds.)CrossRefGoogle Scholar

3) Conway, B.E., in The Liquid State and its Electrical Properties, NATO ASI Series B, 193 (1988).Google Scholar

4) Howie, A., J. Microsc., 180, pt. 3 (1995) 192.CrossRefGoogle Scholar

5) Joy, D.C. and S. Lou, , Scanning, 11 (1989) 176.CrossRefGoogle Scholar

6) Williams, F. et al., J. Chem. Phys., 64 (1976) 1549.CrossRefGoogle Scholar

7) Goulet, T. et al., Chem. Phys. Lett., 170 (1990) 492.CrossRefGoogle Scholar

8) Cameron, R.E. and Donald, A.M., J. Microsc., 173, pt. 3 (1994) 227.CrossRefGoogle Scholar

9) Birkhoff, R.D. et al., in Chemical Spectroscopy and Photochemistry in the Vacuum-Ultraviolet, NATO ASI Series C, 8 (1974).Google Scholar

10) The authors wish to acknowledge helpful discussions with Prof. A. Howie. Support for this work was provided by the BBSRC and Dalgety.Google Scholar