Annealing Effect of Mn thin Films on GaAs

Thin Mn films were deposited on GaAs(100) surfaces at room temperature by a thermal evaporation system followed by annealing at 500 A degrees C for times ranging from 2 to 8 h in nitrogen atmosphere. X-ray diffraction shows that for samples annealed at 500 A degrees C, the interfacial reaction results in the formation of different phases such as Mn2As, MnAs and Mn3Ga. Rutherford Backscattering Spectrometry indicates a diffused layer of Mn-Ga-As system along with some minor oxygen content. Magnetization study done at 10 K shows M-H curve comprising a ferromagnetic and antiferromagnetic part and M-T measurement done from 10 to 300 K shows a transition around 45 K which may be related to the presence of GaMnAs alloy along with the presence of the above binary phases.