Spin correlations and fluctuations in the 3d -transition-metal-based icosahedral quasicrystal Zn-Fe-Sc have been investigated by neutron scattering using polycrystalline samples. Magnetic diffuse scattering has been observed in the elastic experiment at low temperatures, indicating development of static short-range-spin correlations. In addition, the inelastic scattering experiment detects a Q -independent quasielastic signal ascribed to single-site relaxational spin fluctuations. Above the macroscopic freezing temperature Tf 7 K, the spin relaxation rate shows Arrhenius-type behavior, indicating thermally activated relaxation process. In contrast, the relaxation rate remains finite even at the lowest temperature, suggesting a certain quantum origin for the spin fluctuations below Tf.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2008 Jan 29