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arXiv · 1901.06874

The magnetic structure and spin-flop transition in the A-site columnar-ordered quadruple perovskite $\mathrm{TmMn_3O_6}$

A. M. Vibhakar·D. D. Khalyavin·P. Manuel·L. Zhang·K. Yamaura·P. G. Radaelli·A. A. Belik·R. D. Johnson
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Abstract

We present the magnetic structure of $\mathrm{TmMn_3O_6}$, solved via neutron powder diffraction - the first such study of any $R\mathrm{Mn_3O_6}$ A-site columnar-ordered quadruple perovskite to be reported. We demonstrate that long range magnetic order develops below 74 K, and at 28 K a spin-flop transition occurs driven by $f$-$d$ exchange and rare earth single ion anisotropy. In both magnetic phases the magnetic structure may be described as a collinear ferrimagnet, contrary to conventional theories of magnetic order in the manganite perovskites. Instead, we show that these magnetic structures can be understood to arise due to ferro-orbital order, the A, A$'$ and A$''$ site point symmetry, $mm2$, and the dominance of A-B exchange over both A-A and B-B exchange, which together are unique to the $R\mathrm{Mn_3O_6}$ perovskites.

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A. M. Vibhakar, D. D. Khalyavin, P. Manuel, L. Zhang, K. Yamaura, P. G. Radaelli, A. A. Belik, R. D. Johnson. 2019-01-21. The magnetic structure and spin-flop transition in the A-site columnar-ordered quadruple perovskite $\mathrm{TmMn_3O_6}$. https://doi.org/10.1103/physrevb.99.104424

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