The high-temperature ferromagnet MnBi continues to receive attention as a candidate to
replace rare-earth-containing permanent magnets in applications above room temperature.
This is due to a high Curie temperature, large magnetic moments, and a coercivity that
increases with temperature. The synthesis of MnBi also allows for crystals that are free of
interstitial Mn, enabling more direct access to the key interactions underlying the physical
properties of binary Mn-based ferromagnets. In this work, we use inelastic neutron scattering …