Raman scattering study on diluted magnetic semiconductor Ga1-xMnxAs prepared by Mn-ion implantation

Raman scattering measurements have been performed in diluted magnetic semiconductor Ga_1-xMn_xAs prepared by Mn-ion implantation, deposition, and post-annealing technique. It is found that the Raman spectrum measured from the implanted surface of the sample shows some new weak modes in addition to the GaAs-like modes which are observed from the unimplanted surface. The new vibrational modes observed are assigned to MnAs-like modes. The coupled LO-phonon plasmon mode, and Mn and As related vibrational modes caused by Mn-ion implantation, deposition, and post-annealing are also observed. Furthermore, the GaAs-like modes are found to be shifted by approximately 4 cm^-1 in the lower frequency side, compared with those observed from the unimplanted surface.