Magnetic phase transitions and magnetoelectric coupling of GdFeO_3 single crystals probed by low-temperature heat transport

TL;DR

This study investigates how magnetic field influences low-temperature heat transport in GdFeO_3 single crystals, revealing hysteresis linked to ferroelectric domain walls and magnetic transitions, highlighting magnetoelectric coupling.

Contribution

It demonstrates the magnetic field-dependent hysteretic thermal conductivity in GdFeO_3 and connects it to ferroelectric domain wall scattering, providing insights into magnetoelectric interactions.

Findings

Thermal conductivity shows hysteresis depending on magnetic field history.

Irreversible heat transport correlates with ferroelectricity.

Magnetic field can control ferroelectric domain structures.

Abstract

The low-temperature thermal conductivity (\kappa) of GdFeO_3 single crystals is found to be strongly dependent on magnetic field. The low-field \kappa (H) curves show two "dips" for H \parallel a and only one "dip" for H \parallel c, with the characteristic fields having good correspondence with the spin-flop and the spin-polarization transitions. A remarkable phenomenon is that the subKelvin thermal conductivity shows hysteretic behaviors on the history of applying magnetic field, that is, the \kappa(H) isotherms measured with field increasing are larger than those with field decreasing. Intriguingly, the broad region of magnetic field (\sim 0--3 T) showing the irreversibility of heat transport coincides with that presenting the ferroelectricity. It is discussed that the irreversible \kappa(H) behaviors are due to the phonon scattering by ferroelectric domain walls. This result shows an experimental feature that points to the capability of controlling the ferroelectric domain structures by magnetic field in multiferroic materials.