Symmetry of Magnetically Ordered Quasicrystals

TL;DR

This paper reexamines magnetic symmetry in icosahedral quasicrystals, establishing a relation between spin space groups and diffraction patterns, and provides a classification scheme for magnetically ordered quasiperiodic crystals.

Contribution

It introduces a symmetry classification scheme for magnetically ordered quasiperiodic crystals and predicts diffraction patterns based on icosahedral spin space groups.

Findings

Relation between spin space groups and diffraction patterns established

Symmetry classification scheme for magnetically ordered quasiperiodic crystals proposed

Predictions made for diffraction patterns of icosahedral crystals

Abstract

The notion of magnetic symmetry is reexamined in light of the recent observation of long range magnetic order in icosahedral quasicrystals [Charrier et al., Phys. Rev. Lett. 78, 4637 (1997)]. The relation between the symmetry of a magnetically-ordered (periodic or quasiperiodic) crystal, given in terms of a ``spin space group,'' and its neutron diffraction diagram is established. In doing so, an outline of a symmetry classification scheme for magnetically ordered quasiperiodic crystals is provided. Predictions are given for the expected diffraction patterns of magnetically ordered icosahedral crystals, provided their symmetry is well described by icosahedral spin space groups.