Possible contributions of phases to magnetization of the Nd–Dy–Fe–Co–B sintered materials and temperature dependence of the magnetization

Magnetic and structural characteristics of the main phases contained in the Nd–Dy–Fe–Co–B magnetically hard materials (in particular, (Nd$_{0.33}$Dy$_{0.67}$)$_{1}$(Fe$_{0.60}$Co$_{0.40}$)$_{4.74}$B$_{1.12}$ and (Nd$_{0.90}$Dy$_{0.10}$)(Fe$_{0.61}$Co$_{0.39}$)$_{3.13}$ intermetallic compounds) are studied. Parameters of unit cells, saturation magnetizations at 80 and 350 K, and the temperature dependence of the magnetization in the presence of a field of 800 kA/m at temperatures ranging from 320 to 600 K are analyzed. It is shown that the above compounds provide 10–15% contribution to the magnetization of the Nd–Dy–Fe–Co–B sintered magnets even at relatively low concentrations of up to 20%. The results can be used to separate contributions of the main and secondary phases in sintered magnets with different compositions.