Fig. 4: Crystal field model for TbMn6Sn6.
From: Orbital character of the spin-reorientation transition in TbMn6Sn6
a Crystal electric field (CEF) energy levels for a J = 6 Tb ion with dominant \({B}_{2}^{0}\) and \({B}_{4}^{0}\) terms. The orange arrow indicates the experimental values with \({B}_{2}^{0}=-0.0347\) meV and \({B}_{4}^{0}=-0.00143\) meV. b The Zeeman splitting of the CEF levels due to the molecular field acting on the Tb ion. The vertical line shows the estimated ground state molecular field strength of \({B}_{MF}^{{{{{{{{\rm{Tb}}}}}}}}}=22.2\) meV and the blue arrow labels the only dipole-allowed transition out of the ground state. Orbital states are labeled as \(\left|{m}_{J}\right\rangle\). c Tb state populations as a function of temperature, where the molecular field decreases according to the measured Mn sublattice magnetization25. TSR indicates the spin-reorientation transition.
