Far-Infrared Study of DX-Like Centers in Pb$\text{}_{0.95}$Mn$\text{}_{0.05}$Te(Ga)

We present far-infrared reflection spectra of Pb$\text{}_{0.95}$Mn$\text{}_{0.05}$Te single crystal doped with gallium between 10 and 300 K. The analysis of the far-infrared reflection spectra was made by a fitting procedure based on the model of coupled oscillators. Together with the strong plasmon-phonon coupling we obtain three local modes of gallium at about 122 cm$\text{}^{-1}$, 166 cm$\text{}^{-1}$, and 192 cm$\text{}^{-1}$. The position of these modes depends on impurity center charge, and their intensity depends on temperature.