OBSERVATION OF QUASIMAGNETIC STRUCTURES IN RARE-EARTH-BASED ICOSAHEDRAL QUASI-CRYSTALS

The first observation of long-range quasiperiodic antiferromagnetic st ructures in quasicrystals, namely the heavy rare-earth-based icosahedr al R8Mg42Zn50 compounds (R = Tb, Dy, Ho, Er), is reported. This quasim agnetic ordering is characterized by the propagation vector Q = (1/4,0 ,0,0,0,0) in the six-dimensional notation. Simultaneously, broad magne tic peaks appear in the neutron diffraction patterns, characteristic o f a short-range ordering. The coexistence of two different magnetic co rrelation lengths suggests the presence of two types of crystallograph ic sites for the rare-earth atoms.