Magnetic ordering and magnetodielectric phenomena in CoSeO₄

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.