Indexed on: 01 Dec '76Published on: 01 Dec '76Published in: Zeitschrift für Physik B Condensed Matter
Mössbauer spectra of119Sn in Sn1−zEuzMo6S8 (z=0, 1/3, 2/3) have been measured in the temperature range 4.9 K≦T≦293 K. The spectra consist of a quadrupole doublett with unequal intensities at all temperatures. The Debye-Waller factor, the isomeric shift and the asymmetry of the intensity of the quadrupole components show irregularities between 50 K and 110 K which are interpreted as arising from a structural phase transition. The temperature dependence of the Debye-Waller factor can be approximated by a simple phonon spectrum. No quantitative explanation can be given for the large values of the asymmetry. Evidence is presented that this behavior is connected with the properties of the librational modes of the Mo6S8-units in the crystal.