Quantification of dislocation structures at high resolution by atomic force microscopy of dislocation etch pits

Atomic force microscopy of dislocation etch pit structures is a convenient means of characterising the dislocation structure in etchable materials at high resolution for dislocation spacing extending down to 25 nm . This is demonstrated for single crystals of CaF₂. The local deformation zone generated around nanoindents at ambient temperature and the low-angle boundaries generated in the bulk during uniaxial compression at elevated temperatures are presented as examples.     

Etch pitting and subsurface pore growth during the thermal etching of silver

The thermal etching of silver was extensively studied in the middle of twentieth century, revealing the key role of oxygen on surface morphology changes including: grains striation, grain-boundary grooving and etch pitting. Here we probe the role of the subsurface and defects induced by rolling on the thermal etching of pure silver sheet. Nanometre- and micrometre-sized faceted pores have been observed in the subsurface region after heat treatments in air. The relationship between these subsurface pores and rolling defects is demonstrated. A mechanism for the formation of subsurface pores based on the precipitation/reaction of dissolved oxygen is suggested which can also explain the aligned etch pitting observed.