Magnetic properties of InMnAs nanodots prepared by MOVPE

Abstract Ferromagnetic properties of self assembled In 1− x Mn x As nanodots prepared by low pressure metalorganic vapor phase epitaxy were studied. Nanodot structures were grown on (100) GaAs substrates at the temperature of 500 °C and reactor pressure of 100 mbar. Magnetization measurements indicated that up to MnAs molar fraction of x ∼0.143, nanodot structures presented typical properties of diluted magnetic semiconductors, i.e. Curie temperature depends on the Mn content in the alloy. Above this molar fraction, the Curie temperature becomes constant at the value of 353 K. Electron diffraction patterns showed presence of two zinc-blende structures with different lattice constants. We suppose that zinc-blende MnAs is responsible for this behavior. No presence of NiAs structure that is typical for common hexagonal MnAs was observed.