Frustrated magnetism in the J1−J2 honeycomb lattice compounds MgMnO3 and ZnMnO3 synthesized via a metathesis reaction

Abstract

We investigated the magnetic properties of the ilmenite-type manganates $\mathrm{MgMn}{\mathrm{O}}_{3}$ and $\mathrm{ZnMn}{\mathrm{O}}_{3}$, both of which are composed of a honeycomb lattice of magnetic $\mathrm{M}{\mathrm{n}}^{4+}$ ions. Both compounds show antiferromagnetic order with weak ferromagnetic moments. In particular, $\mathrm{MgMn}{\mathrm{O}}_{3}$ exhibits a magnetization ``reversal'' behavior which can be described by the $N$-type ferrimagnetism in the N\'eel's classification. The relationship between the magnetic properties and the crystal and magnetic structures probed by the neutron diffraction experiments indicates that the two honeycomb lattice magnets have different ${J}_{1}\ensuremath{-}{J}_{2}$ parameter sets, placing them in the distinct regions in the phase diagram; both nearest neighbor (NN) and next nearest neighbor (NNN) exchange interactions are antiferromagnetic in $\mathrm{MgMn}{\mathrm{O}}_{3}$, while NN and NNN interactions become ferromagnetic and antiferromagnet, respectively, in $\mathrm{ZnMn}{\mathrm{O}}_{3}$.