Spin dynamics in i-R8Mg42Zn50 quasicrystals (R = Gd, Tb, Dy)

Spin dynamics has been investigated in icosahedral R8Mg42Zn50 quasicrystals (R = Gd, Tb, Dy) by means of muon spin relaxation experiments. Two distinc t components are clearly observed, one of them being a fast relaxing signal with a stretched exponential form as in some disordered systems. The corre sponding depolarization rate strongly increases when the temperature approa ches the ordering temperature T-N defined by neutron diffraction experiment s. Crystal held effects seem to be noticeable, especially in the dysprosium compound. (C) 1999 Elsevier Science B.V. All rights reserved.