INELASTIC NEUTRON SCATTERING MEASUREMENTS ON ND2FE14B SINGLE CRYSTALS

Abstract Inelastic neutron scattering measurements have been carried out on a Nd 2 Fe 14 B single crystal. A strongly temperature-dependent magnon dispersion curve has been found along the high-symmetry direction [0, 0, 1] with a gap at (0, 0, 2). Soft mode behaviour at spin wave vector q c = 0 was observed near the spin reorientation temperature. The inelastic scattering intensity decreases steeply for larger q c . Therefore the dispersion curve could be measured until the middle of the Brillouin zone only. The dispersion is discussed in the frame of a classical spin wave model. In addition to the magnons we could identify two acoustic phonon modes whose energies are in good agreement with the sound velocity as previously determined in a polycrystalline sample of Nd 2 Fe 14 B.