Observation of soft TO phonon modes in Pb1-xGexTe by Raman scattering in the near-infrared (λ=1.064μm)

Abstract

The structural phase transition in Pb1-xGexTe was examined using Raman scattering by soft transverse optical phonon modes (q to 0). An infrared laser ( lambda =1.064 mu m) was employed to increase the scattering volume. The results are consistent with a second-order type of phase transition, which can occur in this pseudo-binary system according to a group theoretical analysis. Samples with Ge content x where 3.5<or=x<or=13.4% were studied.