Raman scattering from the vibrational modes inZn1−xMnxTe

Abstract

We report the observation of Raman scattering associated with the vibrational modes in the diluted magnetic semiconductor ${\mathrm{Zn}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Te. The low-frequency two-phonon density-of-states features in ${\mathrm{Zn}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Te, similar to those of ZnTe, exhibit composition-dependent Raman shifts. Low-frequency disorder-induced one-phonon density-of-states features are also present in the Raman spectra for x≥0.10. The optical phonons of ${\mathrm{Zn}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Te exhibit a variation with x that is intermediate between the two-mode and one-mode situations. The optical modes of ${\mathrm{Zn}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Te are compared with those of ${\mathrm{Cd}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Mn}}_{\mathrm{x}}$Te, the prototype of wide-band-gap diluted magnetic semiconductors. A random-element isodisplacement model is used to describe the behavior of the optical phonons of both alloy systems.