Note on the effect of cobalt substitution on the hard magnetic properties of NdFeC ingot magnets

Abstract The effect of cobalt substitution on the hard magnetic properties of NdFeC-type ingot magnets was studied. It was found that cobalt substitution led to a significant decrease in the field strength needed to magnetize the ingot magnets. A simple production route is described which leads to an isotropic ingot magnet with ( BH max = 70 kJ m −3 , B R = 0.65 T and J H c =800 kA m −1 . The temperature coefficient ( β =−0.6% K −1 ) of these magnets is the same as that of sintered NdFeB-type magnets.