Far infrared study of some rare earth impurities in crystals of Pb 1-xSnx alloys

Abstract

Single crystal samples of Pb0.9Sn0.1Te doped with Yb, Sm or Gd were produced using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for highly polished samples with various impurity concentration (between 0.2 at% and 1 at %). The experimental diagrams were numerically analyzed using a fitting procedure based on the plasma-phonon interaction model and the optical parameters were determined. The application of lead- tin tellurides doped with rare earth elements for infrared astronomy has been discussed.