Observation of Quasimagnetic Structures in Rare-Earth-Based Icosahedral Quasicrystals

The first observation of long-range quasiperiodic antiferromagnetic structures in quasicrystals, namely the heavy rare-earth-based icosahedral R8Mg42Zn50 compounds (R=Tb , Dy, Ho, Er), is reported. This quasimagnetic ordering is characterized by the propagation vector Q=((1)/(4),0,0,0,0,0) in the six-dimensional notation. Simultaneously, broad magnetic peaks appear in the neutron diffraction patterns, characteristic of a short-range ordering. The coexistence of two different magnetic correlation lengths suggests the presence of two types of crystallographic sites for the rare-earth atoms. copyright 1997 The American Physical Society