Far infrared reflectivity spectra of lead-telluride doped with Ytterbium

Single crystal samples of lead-telluride doped with Ytterbium were made using the Bridgman method. Far infrared reflectivity spectra in the temperature range from 10 to 300 K were measured. Analysis of the experimental spectra was made using a fitting procedure based on the model of plasma-phonon interactions and the optical parameters were calculated. Two local impurity modes of Ytterbium were observed at about 160 and 250 cm−1.