Band filling control of the Dzyaloshinskii-Moriya interaction in weakly ferromagnetic insulators

We observe and explain theoretically a dramatic evolution of the Dzyaloshinskii-Moriya interaction in the series of isostructural weak ferromagnets, MnCO$_3$, FeBO$_3$, CoCO$_3$ and NiCO$_3$. The sign of the interaction is encoded in the phase of x-ray magnetic diffraction amplitude, observed through interference with resonant quadrupole scattering. We find very good quantitative agreement with first-principles electronic structure calculations, reproducing both sign and magnitude through the series, and propose a simplified `toy model' to explain the change in sign with 3 d shell filling. The model gives a clue for qualitative understanding of the evolution of the DMI in Mott and charge transfer insulators.

G. Beutier, S. P. Collins, O. V. Dimitrova, V. E. Dmitrienko, M.I. Katsnelson, Y.O. Kvashnin, A.I. Lichtenstein, V. V. Mazurenko, G. Nisbet, E. N. Ovchinnikova, D. Pincini · 2017