Transmission electron microscopy has been used to observe Al segregation around the threading dislocations in Al 0.1 Ga 0.9 N and Al 0.3 Ga 0.7 N grown by metalorganic chemical vapor deposition on 6H-SiC. Dislocation lines were found to have up to 70% more Al concentration than those regions free of dislocations in the matrix. The Al-depleted regions around the dislocations are shown to be within a few nanometers from the dislocation lines. The results also show that more Al segregate to edge dislocations than to screw ones.

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Self-assembled In1−xMnxAs quantum dots (0.19⩽x⩽0.45) have been grown on GaAs (100) substrates by low-temperature molecular beam epitaxy. The microstructure analysis revealed that the uniformly distributed In1−xMnxAs dots have a zinc blende structure as x⩽0.38. Furthermore, all samples exhibit ferromagnetic state at 5K, and their Curie temperatures range from 260to340K varying with x. These (In, Mn)As quantum dots are promising for room-temperature spintronic devices.

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