MAGNETIC EXCITATIONS IN THE HALF-METALLIC NIMNSB FERROMAGNET - FROM HEISENBERG-TYPE TO ITINERANT BEHAVIOR

Magnetization, transport and inelastic neutron scattering experiments were performed on single crystals of the half metallic ferromagnet NiM nSb. A change in behaviour is observed near 80 K in the temperature de pendence of magnetization and resistivity. Magnons were followed up to excitation energies of 70 meV, where they become overdamped due to th e crossing of a Stoner mode. The magnetic behaviour seems to evolve fr om Heisenberg-like at low energies and low temperatures to itinerant m agnetism at high temperatures and high excitation energies.