The incommensurate magnetic structure of YMn2O5: a stringent test of the multiferroic mechanism

TL;DR

This study determines the incommensurate magnetic structure of YMn2O5 using neutron diffraction, confirming the exchange-striction mechanism as the primary cause of its multiferroic properties.

Contribution

It provides a detailed magnetic structure analysis of YMn2O5 and validates the exchange-striction mechanism as the origin of ferroelectricity in this material.

Findings

Magnetic structure determined via neutron diffraction.

Electrical polarization aligns with the b axis.

Exchange-striction identified as the main ferroelectric mechanism.

Abstract

We have determined the magnetic structure of the low-temperature incommensurate phase of multiferroic YMn2O5 using single-crystal neutron diffraction. By employing corepresentation analysis, we have ensured full compliance with both symmetry and physical constraints, so that the electrical polarization must lie along the b axis, as observed. The evolution of the spin components and propagation through the commensurate-incommensurate phase boundary points unambiguously at the exchange-striction mechanism as the primary driving force for ferroelectricity.