# Dzyaloshinskii-Moriya interaction and the magnetic ground state in magnetoelectric LiCoPO$_4$

## TL;DR

This study uses neutron diffraction to analyze the magnetic structures of LiCoPO₄, revealing spin canting and the role of Dzyaloshinskii-Moriya interaction in its magnetoelectric properties.

## Contribution

It provides detailed insights into the magnetic ground state and the influence of Dzyaloshinskii-Moriya interaction in LiCoPO₄, advancing understanding of its magnetoelectric effect.

## Key findings

- Spontaneous spin canting of 7 degrees at zero field.
- Magnetic point group identified as m'_z.
- Field-induced spin canting due to Dzyaloshinskii-Moriya interaction.

## Abstract

Magnetic structures are investigated by means of neutron diffraction to shine a light on the intricate details that are believed to be key to understanding the magnetoelectric effect in LiCoPO$_4$ . At zero field, a spontaneous spin canting of $\varphi = 7(1)^{\circ}$ is found. The spins tilt away from the easy $b$-axis toward $c$. Symmetry considerations lead to the magnetic point group $m'_z$, which is consistent with the previously observed magnetoelectric tensor form and weak ferromagnetic moment along $b$. For magnetic fields applied along $a$, the induced ferromagnetic moment couples via the Dzyaloshinskii-Moriya interaction to yield an additional field-induced spin canting. An upper limit to the size of the interaction is estimated from the canting angle.