Crystals of the semiconductors Pb0. 78Sn0. 22Te and Pb0. 80Sn0. 20Te: In were grown by Bridgman method, and investigated by Mössbauer spectroscopy and X-ray diffraction. Mössbauer spectra were taken at temperatures between 80 and 300 K. The absence of the quadrupole splitting shows a cubic symmetry of the environment for the tin atom, which is in accordance with X-ray data. The temperature dependence of the spectral area is discussed and the Debye temperature is estimated.
