Carbon coating objects for SEM/EDS

Suzanne Davis <davissl [at] umich__edu> asked for "opinions/experiences in
using a coating on small objects for SEM."

I have removed carbon coatings, applied by vaporising carbon in the
usual way for SEM, from samples of objects. The main difference
between removing the carbon from a glass slide or polished specimen
and removing it from an object is the condition of the surface. The
stone seal will have far more pores, cracks and deformities in the
surface than a glass slide and there is a risk that some carbon may
remain. However, some of the thin-sections I had to clean were
relatively rough and had minute cracks and pores. Examination of the
surface after cleaning using transmitted light did not reveal any
carbon remaining.

Technically, I suppose the procedure is sublimating the carbon
(solid to gas) not evaporation (liquid to gas). Hope this helps,

Helena Jaeschke
Archaeological conservator


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                  Conservation DistList Instance 17:53
                Distributed: Wednesday, February 4, 2004
                       Message Id: cdl-17-53-004
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