Subgrain structure and dislocation density of annealed MCT

X-ray topography (reflexion Lang method) was employed to observe the subgrain structure of MCT (Hg1-xCdxTe with x=0.2) after annealings under different conditions. Dislocation density (δ) was evaluated in chemically etched MCT specimens both by optical and electron scanning microscopies. Ingots were grown by the Bridgman method. Cutting, polishing and etching conditions of MCT wafers are specified. Dislocation density of wafers of ingots I (annealed 10 days at 610°C) was δ≅108 cm-2 while that of ignots II (annealed 30 days at 650°C) was of δ≅106 cm-2. Micrographic and X-ray topography observations revealed results in agreement as regards to the mean area values of sub-grain substructure as well as to the misorientation angles between neighbouring subgrains.