Magnetic frustration, phase competition and the magneto-electric effect in NdFe3(BO3)4

TL;DR

This study investigates the magnetic and electric properties of NdFe3(BO3)4, revealing that magnetic frustration and phase competition, rather than non-collinear spin order, drive its magneto-electric effects, using element-specific resonant x-ray scattering.

Contribution

It demonstrates that magnetic frustration causes phase competition in NdFe3(BO3)4, clarifying the origin of its magneto-electric response and excluding non-collinear spin order as the cause.

Findings

Magnetic order of Nd is induced by Fe spin order.

Helicoidal spin order is suppressed by magnetic field, favoring collinear order.

Magneto-electric response is linked to phase competition caused by magnetic frustration.

Abstract

We present an element selective resonant magnetic x-ray scattering study of NdFe3(BO3)4 as a function of temperature and applied magnetic field. Our measurements show that the magnetic order of the Nd sublattice is induced by the Fe spin order. When a magnetic field is applied parallel to the hexagonal basal plane, the helicoidal spin order is suppressed and a collinear ordering, where the moments are forced to align in a direction perpendicular to the applied magnetic field, is stabilized. This result excludes a non-collinear spin order as the origin of the magnetically induced electric polarization in this compound. Instead our data imply that magnetic frustration results in a phase competition, which is the origin of the magneto-electric response.