Effect of Ga addition to the Pr3(Fe,Co,Ti)29 (3:29) system

Polycrystalline Ga-substituted Pr3(Fe1−xCox)27.5Ti1.5 (x=0.3,0.4) magnets have been studied for high temperature permanent magnets. Using x-ray diffraction, in addition to the majority 3:29 phase, the presence of the minority 2:17, 1:12 and α-Fe phases was observed. An increase in TC was observed with increasing Co content. A TC as high as 572 °C was observed for x=0.4. Magnetic measurements at room temperature showed an increase in the anisotropy field HA with increasing Co and Ga concentration, while the coercivity decreased. Scanning electron microscopy and energy dispersive x-ray analysis measurements indicated the 3:29 phase as the majority phase.