Polar magnetization unveiled by polarized neutron diffraction

TL;DR

This paper demonstrates how polarized neutron diffraction can reveal polar magnetization in materials with non-centrosymmetric ions, providing detailed insights into magnetic structures and interactions, including the Dzyaloshinskii-Moriya interaction.

Contribution

It presents symmetry-based simulations of polarized neutron scattering for haematite, offering new insights into magnetic motifs and challenging recent claims about Dzyaloshinskii-Moriya interaction direction.

Findings

Simulations show detailed information on magnetic motifs.

Polarized neutron scattering can challenge previous D-M interaction claims.

Provides a method to analyze polar magnetism in non-centrosymmetric sites.

Abstract

Polar magnetism is present when ions occupy sites that are not centres of inversion symmetry. Fortunately, such magnetization contributes to neutron scattering that is the bedrock of magnetic structure determinations. Experiments in which the scattered neutron polarization is analysed are not a novelty. Simulations of polarized neutron scattering amplitudes for room temperature haematite (alpha-Fe2O3) demonstrate the wealth of information on offer. Two magnetic motifs distinguished by the orientation of their bulk ferromagnetism are considered. Additionally, the symmetry-inspired simulations challenge a recent claim to have determined the absolute direction of the Dzyaloshinskii-Moriya (D-M) interaction.