Canted Eu magnetic structure in EuMnSb2

Abstract

Magnetic ordering breaks the time-reversal symmetry, greatly impacting material topological properties. We report the investigation of the magnetic properties of the layered $\mathrm{EuMnS}{\mathrm{b}}_{2}$, which has two sets of magnetic sublattices. Both the magnetization and electrical resistivity reveal two phase transitions with one at ${T}_{\mathrm{N},\mathrm{Eu}}\ensuremath{\sim}21\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and the other at ${T}_{\mathrm{N},\mathrm{Mn}}\ensuremath{\sim}346\phantom{\rule{0.16em}{0ex}}\mathrm{K}$. Single crystal neutron diffraction refinement indicates that both transitions are originated from magnetic ordering. Below ${T}_{\mathrm{N},\mathrm{Mn}},$ the Mn sublattice forms the C-type antiferromagnetic (AFM) structure with moments [$(4.5\ifmmode\pm\else\textpm\fi{}0.6){\ensuremath{\mu}}_{B}$ at 7 K] pointing along the $a$ axis. Below ${T}_{\mathrm{N},\mathrm{Eu}}$, the Eu sublattice forms the canted A-type AFM structure with moments [$(5.9\ifmmode\pm\else\textpm\fi{}0.8){\ensuremath{\mu}}_{\mathrm{B}}$ at 7 K] lying in the $ac$ plane but pointing (41 \ifmmode\pm\else\textpm\fi{} 1)\ifmmode^\circ\else\textdegree\fi{} away from the $a$ axis. Quantitative analysis indicates that the spin-spin correlation length, while anisotropic, has long-range characteristic in all directions for both the Eu and Mn sublattices.