# Whirling spin order in the quasicrystal approximant Au$_{72}$Al$_{14}$Tb$_{14}$

## TL;DR

This study reveals a long-range antiferromagnetic order with noncoplanar whirling spins in a quasicrystal approximant, highlighting the role of icosahedral symmetry in its magnetic structure.

## Contribution

It introduces a simple icosahedral spin-cluster model with uniaxial anisotropy that explains the observed spin order and metamagnetic transition.

## Key findings

- Confirmed antiferromagnetic order at 10.4 K
- Identified noncoplanar whirling spin structure
- Model explains in-field metamagnetic transition

## Abstract

Neutron powder diffraction experiment has been performed on the quasicrystal approximant Au$_{72}$Al$_{14}$Tb$_{14}$, a body-center-cubic crystal of icosahedral spin clusters. The long-range antiferromagnetic order was confirmed at the transition temperature $T_{\rm N} = 10.4$ K. The magnetic structure consists of noncoplanar whirling spins on the icosahedral clusters, arranging antiferroic-manner. A simple icosahedral spin-cluster model with uniaxial anisotropy accounts well the whirling spin order as well as the in-field metamagnetic transition, indicating that the icosahedral symmetry is essential.