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

Polycrystalline Ga-substituted Pr-3(Fe1-xCox)(27.5)Ti-1.5 (x=0.3,0.4) magne ts have been studied for high temperature permanent magnets. Using x-ray di ffraction, in addition to the majority 3:29 phase, the presence of the mino rity 2:17, 1:12 and alpha-Fe phases was observed. An increase in T-C was ob served with increasing Co content. A T-C as high as 572 degrees C was obser ved for x=0.4. Magnetic measurements at room temperature showed an increase in the anisotropy field H-A with increasing Co and Ga concentration, while the coercivity decreased. Scanning electron microscopy and energy dispersi ve x-ray analysis measurements indicated the 3:29 phase as the majority pha se. (C) 2000 American Institute of Physics. [S0021-8979(00)28208-X].