The results show that the room-temperature magnetic properties of the Nd_ 29.0 Pr_ 0.5 Ga_ 0.2 Fe_ 69.1 Nb_ 0.2 B_ 1.0 magnet can reach up to B_r=1.457T,H_ ci =1097kA·m~ -1 and (BH)_m=409kJ·m~ -3 , with a better homogeneity and consistency.
The magnetic properties of Fe(45%) Al 2O 3 exhibit superparamagnetic nature, meanwhile, the MR ratio is proportional to -( M/M s) 2 and the related constant A is about 0.036. From the HRTEM image, it is clear that when the grain size is less than 1 nm, Fe particle exhibits amorphous, while the size is more than 1 nm, it is crystallized.