Crystal-field symmetry restricts the ground-state Kramers doublet of ${\mathrm{ErBr}}_3$ to one of two classes. We show that the compressed octahedral environment selects the class with $\langle {\psi }_{\pm }\left|J^{\pm }\right|{\psi }_{\mp }\rangle =0$, suppressing the lowest-order $J^{\pm }$-mediated exchange. Thermodynamic measurements reveal two zero-field anomalies at 0.375 and 0.200 K. Under an in-plane magnetic field, the thermodynamic response separates into a phase boundary and a broader crossover line. Inelastic neutron scattering measurements at 2 K reveal no well-defined low-energy dispersive magnetic modes. These results connect the ground-state symmetry with the field-dependent thermodynamic response of ${\mathrm{ErBr}}_3$, providing a microscopic starting point for understanding its low-energy magnetic behavior.

Close

PrevNext

View figure in article

• Magnetic anisotropy
• Magnetic interactions
• Magnetic phase transitions
• Magnetism
• Phase diagrams
• Specific heat
• Spin-orbit coupling
• Crystal-field theory
• Inelastic neutron scattering