Magnetic ordering and spin dynamics in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>S</mml:mi><mml:mo>=</mml:mo><mml:mfrac><mml:mn>5</mml:mn><mml:mn>2</mml:mn></mml:mfrac></mml:mrow></mml:math>staggered triangular lattice antiferromagnet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Ba</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>Mn</mml:mi><mml:mi>Te</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
Lisi Li, Narendirakumar Narayanan, Shangjian Jin, Jia Yu, Zengjia Liu, Hualei Sun, Chin‐Wei Wang, Vanessa K. Peterson, Yun Liu, Sergey Danilkin, Dao‐Xin Yao, Dehong Yu, Meng Wang
Abstract
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 $\mathbit{k}=(0.5,0.5,0)$ and N\'eel transition temperature of ${T}_{\text{N}}\ensuremath{\approx}20$ 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 ${J}_{1}=0.27(3)$, meV ${J}_{2}=0.27(3)$ meV, and ${J}_{3}=\ensuremath{-}0.05(1)$ meV, respectively, and a small value of easy-axis anisotropy of ${D}_{zz}=\ensuremath{-}0.01$ meV. We derive a magnetic phase diagram that reveals a collinear stripe-type antiferromagnetic order that is stabilized by the competition between ${J}_{1},\phantom{\rule{4pt}{0ex}}{J}_{2}$, and ${J}_{3}$.