We report studies of the magnetic properties of a staggered stacked triangular lattice ${\mathrm{Ba}}_2\mathrm{Mn}\mathrm{Te}{\mathrm{O}}_6$ using magnetic susceptibility, specific heat, neutron powder diffraction, inelastic neutron scattering measurements, and first-principles density functional theory calculations. Neutron diffraction measurements reveal ${\mathrm{Ba}}_2\mathrm{Mn}\mathrm{Te}{\mathrm{O}}_6$ to be antiferromagnetically ordered with a propagation vector $\mathit{k}=(0.5,0.5,0)$ and Néel transition temperature of $T_{\text{N}}\approx 20$ K. The dominant interaction derived from the Curie-Weiss fitting to the inverse DC susceptibility is antiferromagnetic. Modeling of the inelastic neutron scattering data with linear spin wave theory yielded magnetic exchange interactions for the nearest intralayer, nearest interlayer, and next-nearest interlayer of $J_1=0.27\left(3\right)$, meV $J_2=0.27\left(3\right)$ meV, and $J_3=-0.05\left(1\right)$ meV, respectively, and a small value of easy-axis anisotropy of $D_{zz}=-0.01$ meV. We derive a magnetic phase diagram that reveals a collinear stripe-type antiferromagnetic order that is stabilized by the competition between $J_1,J_2$, and $J_3$.

• Received 5 June 2020
• Revised 22 August 2020
• Accepted 24 August 2020

DOI:https://doi.org/10.1103/PhysRevB.102.094413