Circularly polarised X-rays as a probe of non-collinear magnetic order in multiferroic TbMnO3

TL;DR

This study uses circularly polarized X-ray scattering to investigate the magnetic structure of multiferroic TbMnO3, revealing detailed information about magnetic order and domain control that was previously inaccessible.

Contribution

The paper introduces a novel application of circularly polarized X-ray scattering combined with polarization analysis to resolve magnetic structures and domain states in multiferroic TbMnO3.

Findings

Electric field induces a nearly mono-domain magnetic state

Technique detects the sense of Mn moment rotation

Provides insights into Tb sublattice ordering and phase shifts

Abstract

Non-resonant X-ray magnetic scattering has been used to study the magnetic structure of multiferroic TbMnO3 in its ferroelectric phase. Circularly polarized X-rays were combined with a full polarization analysis of the scattered beam to reveal important new information on the magnetic structure of this canonical multiferroic. An applied electric field is shown to create a magnetic nearly mono-domain state in which the cylcoidal order on the Mn sublattice rotates either clockwise or counter-clockwise depending on the sign of the field. It is demonstrated how this technique provides sensitivity to the absolute sense of rotation of the Mn moments, and to components of the ordering on the Tb sublattice and phase shifts that earlier neutron diffraction experiments could not resolve.