Magnetoelastic Effects and Magnetic Phase Diagram of Multiferroic $DyMn_2O_5$

TL;DR

This study investigates the magnetoelastic coupling in DyMn2O5, revealing lattice anomalies at phase transitions, the influence of Dy moments, and the discovery of a new high-field magnetic phase.

Contribution

It provides detailed magnetostriction measurements along different orientations and identifies a novel high-field phase in DyMn2O5.

Findings

Lattice anomalies occur at magnetic and ferroelectric phase transitions.

Magnetostrictive coefficients are linked to Dy moment order.

A new high-field magnetic phase has been observed.

Abstract

The magnetoelastic coupling in multiferroic $DyMn_2O_5$ is investigated by magnetostriction measurements along the three crystallographic orientations. Strong lattice anomalies as a function of the magnetic field are detected at the low temperature magnetic and ferroelectric phase transitions. The sign and magnitude of the magnetostrictive coefficient as well as the lattice anomalies at the transitions are correlated with the Dy moment order and with the sharp changes of the dielectric constant and the ferroelectric polarization. With the magnetic field applied along the c-axis a new high-field phase has been detected the magnetic structure of which has yet to be explored.