An x-ray resonant diffraction study of multiferroic DyMn2O5

TL;DR

This study uses x-ray resonant scattering to explore the complex magnetic ordering of Dy ions in multiferroic DyMn2O5, revealing multiple wavevectors and a link between magnetic signals and ferroelectric polarization.

Contribution

It provides new insights into the magnetic order and its temperature dependence in DyMn2O5 using resonant x-ray scattering, highlighting complex behaviors similar to other RMn2O5 multiferroics.

Findings

Multiple magnetic wavevectors observed, both incommensurate and commensurate.

A non-magnetic signal correlates with ferroelectric polarization maxima.

Results support theories based on acentric spin-density waves.

Abstract

X-ray resonant scattering has been used to measure the magnetic order of the Dy ions below 40K in multiferroic DyMn$_{2}$O$_{5}$. The magnetic order has a complex behaviour. There are several different ordering wavevectors, both incommensurate and commensurate, as the temperature is varied. In addition a non-magnetic signal at twice the wavevector of one of the commensurate signals is observed, the maximum intensity of which occurs at the same temperature as a local maximum in the ferroelectric polarisation. Some of the results, which bear resemblence to the behaviour of other members of the RMn$_{2}$O$_{5}$ family of multiferroic materials, may be explained by a theory based on so-called acentric spin-density waves.