Magnetization process of Neodymium-Iron-Boron (Nd-Fe-B) sintered magnets investigated by small-angle neutron scattering under external magnetic fields

Akiya, Takahiro*; Kato, Hiroaki*; Takeda, Masayasu  ; Suzuki, Junichi; Yamaguchi, Daisuke; Sagawa, Masato*

The coercive force of Nd-Fe-B sintered magnets depends on several factors. Among those factors, the coercivity is easily affected by the temperature in the so-called low-temperature annealing process. A remarkable structural change of interface between the main phase (NdFeB) and the Nd-rich phase is believed to occur at the temperature where the coercivity reaches the highest value. We performed the small-angle neutron scattering measurements to distinguish the SANS originating in nuclear structure from that in magnetic one. The external magnetic fields were applied parallel to the -axis, and were increased up to 10 kOe every 2 kOe during the measurements. Quantitative analysis of the change of scattering patterns and the magnetization process is reported at the meeting.