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 LiCoPO4. At zero field, a spontaneous spincanting of ϕ = 7(1)° 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 tensorform 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 limitto the size of the interaction is estimated from the canting angle.
Fogh, E., Zaharko, O., Schefer, J., Niedermayer, C., Holm-Dahlin, S., Sørensen, M. K., ... Toft-Petersen, R.
(2019). Dzyaloshinskii-Moriya interaction and the magnetic ground state in magnetoelectric LiCoPO4
. Physical Review B
(10), . https://doi.org/10.1103/PhysRevB.99.104421