A Neutron diffraction study of multiferroics RMn2O5

TL;DR

This paper reviews neutron diffraction studies of RMn2O5 multiferroics, analyzing magnetic structures, phase diagrams, and mechanisms of ferroelectricity, providing insights into their complex magnetic and electric coupling.

Contribution

It offers a comprehensive review of magnetic properties and proposes a minimal model to understand magnetic propagation and ferroelectricity mechanisms in RMn2O5.

Findings

Identification of magnetic phase diagram features

Analysis of coupling between magnetic and electric order

Proposal of a minimal model for magnetic structure propagation

Abstract

The magnetic properties of RMn2O5 multiferrroics as obtained by unpolarized and polarized neutron diffraction experiments are reviewed. We discuss the qualitative features of the magnetic phase diagram both in zero magnetic field and in field and analyze the commensurate magnetic structure and its coupling to an applied electric field. The origin of ferrolectricity is discussed based on calculations of the ferroelectric polarization predicted by different microscopic coupling mechanisms (exchange striction and cycloidal spin-orbit models). A minimal model containing a small set of parameters is also presented in order to understand the propagation of the magnetic structure along the c-direction.