Quadrupole splitting observed in some cubic Laves-phase compounds by means of 169Tm Moessbauer spectroscopy

169Tm Moessbauer spectroscopy has been performed on the cubic Laves-phase compounds TmNi2, TmRh2 and TmIr2 in the temperature range 2-300 K and found well resolved quadrupolar splitting at low temperature. In cubic compounds this feature is uncommon and it is explained as indicating the presence of a static or dynamic distortion. None of the three compounds investigated shows magnetic ordering at 2 K or higher temperatures, nor can any of the three compounds be characterised as a van Vleck paramagnet at low temperatures. (author)