Magnetic properties of single grain r-mg-cd primitive icosahedral quasicrystals (R = Y, Gd, Tb or Dy)

The growth and characterization of single grains of the primitive icosahedral quasicrystal R - Mg - Cd ( R = Y, Gd, Tb or Dy) are described. From the thermodynamic properties, it is confirmed that the system is a spin glass exhibiting the characteristic spin-freezing transition of such systems. There is no evidence for two distinct freezing transitions previously observed for polygrain samples. The bulk magnetic properties and the effect of crystalline electric fields on the spin-freezing temperature are found to be very similar to those of the face-centred icosahedral quasicrystal R - Mg - Zn.