Effect of refractory metals addition on the structural and magnetic properties of Pr3(Fe, Co, Ti)29 system

Abstract Polycrystalline refractory metal-substituted Pr 3 (Fe 0.6 M 0.1 Co 0.3 ) 27.5 Ti 1.5 (M=V, Ti, Zr, Mo, Nb,Cr) and Pr 3 (Fe 0.5 Co 0.5 ) 27.5 Ti 1.5 have been studied for high-temperature permanent magnetic materials. X-ray diffraction showed the main phase to be the 3:29 phase. We observed the highest reported T C (Curie temperature) of 640 °C for the 3:29 system in the Pr 3 (Fe 0.5 Co 0.5 ) 27.5 Ti 1.5 . In the refractory metal-substituted systems, the highest T C of 480 °C was observed for the Nb-substituted alloy. SEM measurements showed that Ti in Pr 3 (Fe 0.6 Ti 0.1 Co 0.3 ) 27.5 Ti 1.5 is deposited near the grain boundary. H A (anisotropy energy) of V-substituted alloy is as high as 72 kOe, the highest reported in the 3:29 system and is ∼200% higher than 24 kOe observed in Pr 3 (Fe 0.7 Co 0.3 ) 27.5 Ti 1.5 . Cr and Ti substitutions show an increase of 65% (40 kOe) and 45% (35 kOe) in H A respectively. M S (saturation magnetization) values were ∼100 emu/g and are lower than that observed in Pr 3 (Fe 0.7 Co 0.3 ) 27.5 Ti 1.5 .