Phases of NdFe10.7-xCoxTi1.3 alloys and magnetic properties of their nitrides

It has been found that the arc-melted NdFe_10.7-xCo_xTi_1.3 (x=0/2/4/6) alloys have nearly single phase of ThMn₁₂-type structure except the small amount of (Fe, Co)2Ti (or Fe₂Ti) and α-Fe phases. The ThMn₁₂-type phase forms as square prisms and (Fe, Co)₂Ti (or Fe₂Ti) exists between the grain boundaries as particles. Nitrification of this alloy system considerably increased the anisotropy field and Curie temperature. The dependence on cobalt content of the magnetic properties before and after the nitrification treatments shows almost the same trend; the Co-substitution increases the Curie temperature but decreases the anisotropy field. In the nitride system studied, NdFe_10.7Ti _1.3N_y has the highest anisotropy field of about 6370 kA/m (80 kOe)