The structure and magnetic properties of PrFe10Mo2Nx compounds prepared by melt spinning have been investigated. A single-phase structure of ThMn12-like has been obtained in ribbons quenched at velocities vs below 40 m/s. The desired ThMn12 structure is considerably more stable for Pr(Fe, Mo)12 compounds than for Nd(Fe, Mo)12 compounds. Only at higher speeds than 50 m/s the PrFe10Mo2 ribbons quench into TbCu7-like compound of which Curie temperature is about 580 K. Annealing temperatures in excess of 1023 K are required to form ThMn12 crystal structure for the ribbons melt spun at 50 m/s. Upon nitrogenation at 723 K, the Curie temperatures increase to 663 and 580 K for TbCu7- and ThMn12-like nitrides, respectively. A coercivity of 3.3 kOe with a magnetization up to 118 emu/g at a field of 20 kOe has been obtained in the present ribbons.

We have succeeded in synthesizing PrFe10VxMo2−x compounds (x=0–1.5) and their nitrides with ThMn12-type structure. The phase formation and magnetic properties have been investigated by x-ray diffraction, differential thermal analysis, and magnetic measurements. It is found that PrFe10V2 compound with ThMn12-type structure does not form and that PrFe10VxMo2−x compounds with ThMn12-type structure can be formed in the as-cast sample (x=0) or by annealing the as-cast samples in a lower temperature (x=0.5–1.5). The substitution of Mo for V in the compounds results in a decrease of the magnetization and Curie temperatures. The PrFe10VxMo2−xNy with x=0–1.5 has a Tc about 416–265 °C. The hard magnetic properties of PrFe10VMoNy magnets prepared by hydrogenation-disproportionation-desorption-recombination technique have been assessed.