SYNTHESIS AND MAGNETIC-PROPERTIES OF R(3)(FE,TI)(29) AND R(3)(FE,TI)(29)N-X (R=CE,PR,GD)

R(3)(Fe,Ti)(29) and R(3)(Fe,Ti)(29)N-x nitrides (R = Ce,Pr,Gd) have been synthesized. The structure is described in the A(2)/(m) space group. The unit cell dimensions change as a function of rare-earth reflecting the lanthanide contraction, except for Ce, which has anomalously low lattice parameters. The unit cell volumes of the nitrides are 5-7% greater than those of the parent alloys. The Curie temperature increases from Ce to Gd with values of 330, 392 and 524 K for Ce, Pr and Gd respectively, and is enhanced by nitrogenation to 670 K for Ce, 721 K for Pr, and 745 K for Gd. The room temperature magnetization at 5 T is 92.0, 130.75 and 86.58 Am-2/kg and increases to 151.88, 164.47 and 118.0 Am-2/kg after nitrogenation for Ce, Pr and Gd respectively.