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 $R_8{\mathrm{Mg}}_{42}{\mathrm{Zn}}_{50}$ compounds ( $R=\mathrm{Tb}$, Dy, Ho, Er), is reported. This quasimagnetic ordering is characterized by the propagation vector $\mathbf{Q}=(\frac{1}{4},0,0,0,0,0\mathrm{})$ 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.