Possibilities for In-situ Observation of Basic Deformation Processes and of Other Dynamic Processes

The purposes of this paper are to discuss the possibilities of HVEM in-situ observation for deriving meaningful results on basic deformation processes by illustrating some examples which have been obtained so far and to assess the capabilities of this method to investigate crystal deformation as well as other dynamic processes. First, the experimental procedures developed by our group in Nagoya to study the dynamic behaviour of dislocations are introduced. Research subjects which have been studied effectively by this method so far are illustrated. The lower safety limit of specimen thickness for deriving information typical of bulk materials, the effects of size and free surfaces of a specimen and the effects of electron irradiation etc. are to be discussed to assess the validity of in situ observation of dislocation behaviours. Some prospects on new applications and extensions of in-situ HVEM for physical and materials research are to be presented, including possibilities for in-situ observation of other subjects such as diffusion, environmental effects, interface reaction, chemical reaction, defect formation during growing or processing of semi-conductors, surface treatment and micro fabrication by electron beam etc.