Neutron scattering study on spin correlations and fluctuations in the transition-metal-based magnetic quasicrystal Zn-Fe-Sc

TL;DR

This neutron scattering study reveals static short-range spin correlations and quantum-origin spin fluctuations in the Zn-Fe-Sc magnetic quasicrystal, highlighting temperature-dependent relaxation behaviors.

Contribution

First investigation of spin correlations and fluctuations in Zn-Fe-Sc quasicrystal using neutron scattering, identifying static correlations and quantum spin dynamics.

Findings

Magnetic diffuse scattering indicates static short-range correlations.

Detection of Q-independent quasielastic scattering shows relaxational spin fluctuations.

Spin relaxation rate exhibits Arrhenius behavior above 7 K and remains finite at low temperatures.

Abstract

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 $T_{\rm f} \simeq 7$ 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 $T_{\rm f}$.