Semiautomatic wet chemical etching of an array of MnAs nanodots and their magnetic properties

MnAs layers grown on GaAs substrates are processed to arrays of submicron-scale islands in a semiautomatic manner by wet chemical etching. Magnetic-force microscopy reveals the importance of the nonuniform material characteristics of MnAs layers originating from the stress for the island formation. The fabrication technique relies on the cracks generated in the MnAs layers by the etching. The stress due to the volume change associated with the phase transition between the α and β phases of MnAs is indicated to be responsible for the crack generation.