Platinum Metals Rev., 1979, 23, (1), 15
Platinum Sputtered Coatings for Scanning Electron Microscopy
The high electron emission and resistance to corrosion of thin noble metal films make them eminently suitable as conductive coatings on scanning electron microscope (S.E.M.) specimens. Gold and its alloys with palladium are most frequently used for this purpose but at the Ninth International Congress on Electron Microscopy held in August, 1978 at Toronto, Canada, a display presentation by I. M. Watt of the Johnson Matthey Research Centre compared coatings of these established materials with those of platinum. Simple sputter coaters, only recently commercially available, and advances in platinum plating technology have now made it practicable to coat S.E.M. specimens with platinum as conveniently as with gold.
A suitable platinum coating needs to be only half the thickness required for gold, resulting in less specimen distortion and giving superior peak-to-background ratio in X-ray analysis. In addition, the lower atomic mobility of newly condensed platinum atoms results in a coating having a finer microstructure which is less influenced by temperature changes and substrate composition.