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arXiv · 1903.08909

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

Ellen Fogh·Oksana Zaharko·Jürg Schefer·Christof Niedermayer·Sonja Holm-Dahlin·Michael Korning Sørensen·Andreas Bott Kristensen·Niels Hessel Andersen·David Vaknin·Niels Bech Christensen·Rasmus Toft-Petersen
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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 $φ= 7(1)^{\circ}$ 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.

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Ellen Fogh, Oksana Zaharko, Jürg Schefer, Christof Niedermayer, Sonja Holm-Dahlin, Michael Korning Sørensen, Andreas Bott Kristensen, Niels Hessel Andersen, David Vaknin, Niels Bech Christensen, Rasmus Toft-Petersen. 2019-03-21. Dzyaloshinskii-Moriya interaction and the magnetic ground state in magnetoelectric LiCoPO$_4$. https://doi.org/10.1103/physrevb.99.104421

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