Magnetic structure and magnetoelectric coupling in antiferromagnet Co5(TeO3)4Cl2

TL;DR

This study investigates the magnetic structure and magnetoelectric effects in the vdW layered multiferroic Co5(TeO3)4Cl2, revealing complex antiferromagnetic order, spin re-orientation, and significant magnetoelectric coupling, highlighting its potential for emergent multiferroic applications.

Contribution

The paper reports the discovery of complex magnetic behavior and strong magnetoelectric coupling in Co5(TeO3)4Cl2, a new vdW multiferroic, providing insights into its magnetic structure and functional properties.

Findings

Non-coplanar antiferromagnetic state with Neel vector along c-axis

Spin re-orientation between 8 K and 15 K due to Co site moments

Maximal linear magnetoelectric coefficient of 45 ps/m

Abstract

The van der Waals (vdW) layered multiferroics, which host simultaneous ferroelectric and magnetic orders, have attracted attention not only for their potentials to be utilized in nanoelectric devices and spintronics, but also offer alternative opportunities for emergent physical phenomena. To date, the vdW layered multiferroic materials are still very rare. In this work, we have investigated the magnetic structure and magnetoelectric effects in Co5(TeO3)4Cl2, a promising new multiferroic compound with antiferromagnetic (AFM) Neel point TN = 18 K. The neutron powder diffraction reveals the non-coplanar AFM state with preferred Neel vector along the c-axis, while a spin re-orientation occurring between 8 K and 15 K is identified, which results from the distinct temperature dependence of the non-equivalent Co sites moment in Co5(TeO3)4Cl2. What is more, it is found that Co5(TeO3)4Cl2 is one of the best vdW multiferroics studied so far in terms of the multiferroic performance. The measured linear ME coefficient exhibits the emergent oscillation dependence of the angle between magnetic field and electric field, and the maximal value is as big as 45 ps/m. It is suggested that Co5(TeO3)4Cl2 is an appreciated platform for exploring the emergent multiferroicity in vdW layered compounds.