亜鉛の転位腐食孔

抄録

Four etchants revealing both fresh and old dislocations as etch pits in zinc (99.999%) crystals were developed. (1) G solution: The chemical composition by volume is 190 parts CH₃COOH, 10 parts 35%H₂O₂, 1∼2 parts 36%HCl, and 50 parts H₂O. This etchant produced etch pits with rhombic shapes and those with arrowhead-like shapes on {2\bar1\bar10} and {3\bar2\bar10} surfaces, respectively. (2) K solution: The composition is 95 parts HCOOH and 5 parts 35%H₂O₂. Etch pits developed on {2\bar1\bar10} surfaces in this solution were rectangular. (3) N solution: The composition is 40 parts CH₃COOH, 10 parts 35%H₂O₂, one part 36%HCl, and 20∼40 parts H₂O. This produced two kinds of etch pits on {10\bar10} surfaces, that is, light (rectangular) and dark (lenticular) pits corresponding probably to basal and non-basal dislocations, respectively. The addition of a small amount of FeCl₃·6H₂O, surfactants, etc. to N solution modified the shape of etch pits. (4) T solution: The composition is 10∼30 parts CH₃COOH, 10∼30 parts 35%H₂O₂, 1∼3 parts 36%HCl, and 1000 parts H₂O. This yielded etch-pits or-grooves on {0001} surfaces corresponding to non-basal dislocations.