The movement of dislocations during the observation of metal films inside an electron microscope

Abstract

The influence of specimen contamination on the movement of dislocations in metal films under observation in the electron microscope has been examined. Complete control of the rate of contamination, arising from the electron bombardment of adsorbed hydrocarbon molecules, has been obtained by placing the specimen in a small chamber containing oxygen at a relatively high pressure. It is found that dislocation movement occurs in thin evaporated single crystal gold films only if contamination is allowed to form on the specimens. The movement is believed to occur as a result of the high tensile stress present in the contamination layer. It is concluded that specimen contamination is, at least, a major contributory factor to the cause of the dislocation movement observed in specimens prepared by electro-thinning of bulk foils.