Magnetic ordering and magnetodielectric phenomena in CoSeO$_4$

TL;DR

This study investigates the magnetic and magnetodielectric properties of CoSeO$_4$, revealing a low-temperature magnetic transition, complex spin arrangements, and field-dependent dielectric behavior, highlighting its potential for multifunctional magnetic materials.

Contribution

It provides detailed insights into the magnetic structure and magnetodielectric coupling in CoSeO$_4$, a material with edge-sharing Co$^{2+}$ chains, which was not previously characterized in this context.

Findings

Magnetic transition occurs below 30 K.

Neutron diffraction reveals antiferromagnetic chains with spin realignment.

Dielectric constant changes slope at magnetic transition and depends on magnetic field.

Abstract

CoSeO$_4$ has a structure consisting of edge-sharing chains of Co$^{2+}$ octahedra which are held together by SeO$_4^{2-}$ tetrahedra via shared oxygen atoms at the edges of the octahedra. DC magnetization measurements indicate a transition to an ordered state below 30 K. Powder neutron diffraction refinements suggest an ordered state with two unique antiferrromagnetic chains within the unit cell. Isothermal magnetization measurements indicate a temperature-dependent field-induced magnetic transition below the ordering temperature. From neutron diffraction, we find this corresponds to a realignment of spins from the canted configuration towards the c-axis. The dielectric constant shows a change in slope at the magnetic ordering temperature as well as a quadratic dependence on the external magnetic field.