Control of ferroelectric polarization via uniaxial pressure in the spin-lattice-coupled multiferroic CuFe1-xGaxO2

TL;DR

This study demonstrates that uniaxial pressure can control ferroelectric polarization in a spin-driven multiferroic material, revealing the role of magnetic domains and lattice distortions in this process.

Contribution

It shows how uniaxial pressure influences ferroelectric polarization via magnetic domain repopulation in CuFe1-xGaxO2, highlighting the spin-lattice coupling mechanism.

Findings

Ferroelectric polarization is controllable by uniaxial pressure.

Magnetic domain populations change with applied pressure.

Spin-lattice coupling underpins the piezoelectric effect.

Abstract

We have demonstrated that ferroelectric polarization in a spin-driven multiferroic CuFe1-xGaxO2 with x = 0.035 can be controlled by the application of uniaxial pressure. Our neutron diffraction and in-situ ferroelectric polarization measurements have revealed that the pressure dependence of the ferroelectric polarization is explained by repopulation of three types of magnetic domains originating from the trigonal symmetry of the crystal. We conclude that the spin-driven anisotropic lattice distortion and the fixed relationship between the directions of the magnetic modulation wave vector and the ferroelectric polarization are the keys to this spin-mediated piezoelectric effect.