MAGNETIC AND CRYSTALLOGRAPHIC PROPERTIES OF NOVEL FE-RICH RARE-EARTH NITRIDES OF THE TYPE RTIFE11N1-DELTA

We succeed in inserting a number of nitrogen atoms into the RTiFe11 intermetallics. The nitrides retain the ThMn12-type structure, but with an increase in the unit cell volume. The crystallographic sites located by nitrogen atoms are determined by using neutron diffraction techniques. The nitrogen atoms are found to have an effect of increasing Curie temperature and saturation magnetization. Moreover, an essential change in magnetocrystalline anisotropy is observed upon nitrogenation. By all of these effects, the NdTiFe11N1-delta compounds have excellent intrinsic magnetic properties favorable for permanent magnet applications.