Prediction of High-Energy Spin-Wave Excitation in Iron

Calculations have been made of inelastic-neutron-scattering cross sections for ferromagnetic iron. Quite unexpectedly, a rich picture of high-energy collective excitations has emerged. In particular, "optic" spin-waves modes with energies ranging to about 750 meV are predicted. Thus, iron is an ideal candidate for a novel high-energy-transfer experiment on recently developed high-energy neutron sources.