Optic spin-waves in magnetite near the Verwey transition

The energies of optic spin waves at a zone centre and a (001) zone boundary have been measured in a natural crystal of magnetite at temperatures in the neighbourhood of the Verwey transition. The energies of these spin waves increased by 0.5 ± 0.4and 0.9 ± 0.5 meV respectively on cooling through the transition and therefore do not exhibit a strong change as a consequence of the ordering of the Fe²⁺ and Fe³⁺ ions at the transition.