We report the observation of Raman scattering associated with the magnetic excitations in diluted magnetic semiconductors, ${\mathrm{Cd}}_{1-x}{\mathrm{Mn}}_x$ Te in particular, in an applied magnetic field. A sharp Raman line due to the spin flip of the $3d$ electrons of ${\mathrm{Mn}}^{2+}$, corresponding to the ${\Delta m}_S=\pm 1$ transition, occurs in the paramagnetic phase. Close to band-gap resonance, the ${\Delta m}_S=\pm 1$ transition in combination with the zone-center LO phonons as well as the ${\Delta m}_S=\pm 2$ transition are present. In addition to the internal transitions of ${\mathrm{Mn}}^{2+}$, this resonance suggests a new Raman mechanism involving interband transitions in conjunction with the exchange interaction between band electrons and ${\mathrm{Mn}}^{2+}$. In the magnetically ordered low-temperature phase, the magnon feature splits into two components in the presence of an applied magnetic field. As the temperature is lowered and the crystal becomes magnetically ordered, the ${\mathrm{Mn}}^{2+}$ spin flip of the paramagnetic phase evolves into the higher-energy component of the magnon.

• Received 14 October 1982

DOI:https://doi.org/10.1103/PhysRevB.27.3471