The compound Sm0.98Fe9.02-xGaxNδ（x=0, 0.25, 0.5, 0.75, 1） were prepared by melt-spun method and subsequent annealing and nitriding. The Rietveld analysis showed that the lattice expansion played an important role i...The compound Sm0.98Fe9.02-xGaxNδ（x=0, 0.25, 0.5, 0.75, 1） were prepared by melt-spun method and subsequent annealing and nitriding. The Rietveld analysis showed that the lattice expansion played an important role in improving the Curie temperature. An obvious development of the Curie temperature was obtained with the increased Ga content from x=0-1 （ΔTc=90 ℃）. The optimum coercivity of nitrides was obtained at x=0.25 with the value Hcj=652 kA/m （8.15 kOe） after annealing, which corresponded to a reasonable distribution of grain sizes of both TbCu7-type SmFe9Nδandα-Fe. However, an excess of Ga doping might lead to an ab-normal growth of α-Fe, which in turn deteriorated the magnetic properties. It was concluded that a moderate Ga content was very ef-fective in raising the coercivity and Curie temperament in the TbCu7-type Sm-Fe-N.展开更多
Nanocrystalline SmFe_（8.95-x）Ga_（0.26）Nb_xN_δ（x=0, 0.1, 0.2, 0.3） were prepared using rapid-quenching,annealing and nitriding. The magnetic properties and crystal structures were systematically studied under va...Nanocrystalline SmFe_（8.95-x）Ga_（0.26）Nb_xN_δ（x=0, 0.1, 0.2, 0.3） were prepared using rapid-quenching,annealing and nitriding. The magnetic properties and crystal structures were systematically studied under various wheel velocities to investigate the influence of Nb doping for the compounds. It is found that TbCu7-type structure is able to be obtained even though the wheel velocity is reduced to 20 m/s（x = 0.3）. An significant increase（△T_c=70 ℃） of the Curie temperature is obtained with Nb doping at x = 0.1 due to the lattice expansion revealed by Rietveld analysis. The optimum coercivity with the value H_（cj） of 810 kA/m is achieved at x = 0.2 in the nitrides, in which a reasonable distribution of grain sizes of both TbCu_7-type SmFe_9 N_δ and α-Fe can be found. However, an excess of Nb doping may lead to the increase of the weight fraction of α-Fe, which in turn deteriorates the magnetic properties.展开更多
基金supported by International Science and Technology Cooperation Project(2010 DFB53520)the National High Technology Research and Development Program of China(2011AA03A402)
文摘The compound Sm0.98Fe9.02-xGaxNδ（x=0, 0.25, 0.5, 0.75, 1） were prepared by melt-spun method and subsequent annealing and nitriding. The Rietveld analysis showed that the lattice expansion played an important role in improving the Curie temperature. An obvious development of the Curie temperature was obtained with the increased Ga content from x=0-1 （ΔTc=90 ℃）. The optimum coercivity of nitrides was obtained at x=0.25 with the value Hcj=652 kA/m （8.15 kOe） after annealing, which corresponded to a reasonable distribution of grain sizes of both TbCu7-type SmFe9Nδandα-Fe. However, an excess of Ga doping might lead to an ab-normal growth of α-Fe, which in turn deteriorated the magnetic properties. It was concluded that a moderate Ga content was very ef-fective in raising the coercivity and Curie temperament in the TbCu7-type Sm-Fe-N.
文摘Nanocrystalline SmFe_（8.95-x）Ga_（0.26）Nb_xN_δ（x=0, 0.1, 0.2, 0.3） were prepared using rapid-quenching,annealing and nitriding. The magnetic properties and crystal structures were systematically studied under various wheel velocities to investigate the influence of Nb doping for the compounds. It is found that TbCu7-type structure is able to be obtained even though the wheel velocity is reduced to 20 m/s（x = 0.3）. An significant increase（△T_c=70 ℃） of the Curie temperature is obtained with Nb doping at x = 0.1 due to the lattice expansion revealed by Rietveld analysis. The optimum coercivity with the value H_（cj） of 810 kA/m is achieved at x = 0.2 in the nitrides, in which a reasonable distribution of grain sizes of both TbCu_7-type SmFe_9 N_δ and α-Fe can be found. However, an excess of Nb doping may lead to the increase of the weight fraction of α-Fe, which in turn deteriorates the magnetic properties.
