On the Direct Observation of the Substructure Network in Iron [Letter to the Editor]

The technique described offers the following advantages compared to the method proposed by Mitchell et al. : 1. It is safer because perchloric acid is eliminated from the electrolyte. 2. Individual dislocation sites are resolved at moderate magnifications by etch pits. 3. Bright field illumination, which is a simpler, more convenient method than phase contrast and provides better resolution, can be used to reveal the substructure