Resonant spin-flip Raman scattering on photoexcited carriers inp-typeCd0.95Mn0.05Te crystals

Abstract

The exchange interaction with magnetic impurities has been studied in p-type ${\mathrm{Cd}}_{0.95}$${\mathrm{Mn}}_{0.05}$Te crystals by means of spin-flip Raman scattering (SFRS). An additional line, active in crossed polarizations, was observed in the Raman spectra under excitation above the energy gap. The spectral shift of the line depends strongly on magnetic field and changes from \ensuremath{\Delta}\ensuremath{\nu}=28 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ to \ensuremath{\Delta}\ensuremath{\nu}=135 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ as the field increases from H=1 T to H=10 T. This SFRS line displays resonant behavior with excitation energies close to the exciton transitions. Analysis of the selection rules and resonance energies for different configurations of scattering enables us to attribute this line to SFRS by photoexcited electrons created in the crystal by band-to-band optical excitation. This conclusion is confirmed by the superlinear behavior of the SFRS intensity as a function of the excitation power. These results provide prospects for the study of the s-d exchange interaction in p-type semimagnetic semiconductors using the SFRS method.