Zinc-blende-type MnAs nanoclusters embedded in GaAs

Structural, magnetic, and magneto-optical properties of GaAs:MnAs granular thin films have been investigated. Zinc-blende(ZB)-type MnAs clusters were found to be formed by annealing GaAs:MnAs at 500 degrees C with a ramp rate of 5 degrees C/min under a nitrogen atmosphere. Magnetic and magneto-optical properties of this GaAs:MnAs granular material with ZB-type MnAs clusters were different from those of the GaAs:MnAs with NiAs-type hexagonal MnAs clusters. The ferromagnetic transition temperature T-C of the GaAs:MnAs of ZB type is estimated to be 360 K, which is higher than T-C (=313 K) of the NiAs-type hexagonal MnAs. (c) 2005 American Institute of Physics.