The interfacial defects of hard magnetic Pr2Fe14B phase from amorphous t o nanostructures have been investigated by positron lifetime spectroscopy. The n anostructure was produced by melt-spinning and nanocrystallizat...The interfacial defects of hard magnetic Pr2Fe14B phase from amorphous t o nanostructures have been investigated by positron lifetime spectroscopy. The n anostructure was produced by melt-spinning and nanocrystallization route. The t wo main components can be ascribed to vacancy-like defects in the intergranular layers or the interfaces,and microvoids or large free volumes with size compar ed to several missing atoms at the interactions of the （atomic） aggregates or the crystallites. The remarkable changes in the positron lifetimes from the amor phous structure to the nanocrystructure with varied sizes can be interpreted,in dicating that the structural transformation and the grain growth induce the defe ct changes occurring at the interfaces with different shapes and sizes.展开更多
High-performance α-Fe/Pr2FelnB-type nanocomposite magnets based on the compositions of PrsFes6B6 microalloyed with Co, Nb and C were fabricated by direct melt spinning. The coercivity was greatly improved from 5.5 kO...High-performance α-Fe/Pr2FelnB-type nanocomposite magnets based on the compositions of PrsFes6B6 microalloyed with Co, Nb and C were fabricated by direct melt spinning. The coercivity was greatly improved from 5.5 kOe for the Pr8Fe86B6 ribbons to 7.4 kOe for the Pr8Fe85NbB5C ribbons. The balanced high coercivity and remanence were obtained in Pr8Fe75Co10NbB5C ribbons due to the Co substitution for Fe, which led to the significant improvement of magnetic properties in these ribbons. A remanence ratio of 0.82, a coercive field of 6.6 kOe and a maximum energy product of 26.2 MGOe in melt-sptm Pr8Fe75Co10NbB5C ribbons were ob- tained at room temperature.展开更多
文摘The interfacial defects of hard magnetic Pr2Fe14B phase from amorphous t o nanostructures have been investigated by positron lifetime spectroscopy. The n anostructure was produced by melt-spinning and nanocrystallization route. The t wo main components can be ascribed to vacancy-like defects in the intergranular layers or the interfaces,and microvoids or large free volumes with size compar ed to several missing atoms at the interactions of the （atomic） aggregates or the crystallites. The remarkable changes in the positron lifetimes from the amor phous structure to the nanocrystructure with varied sizes can be interpreted,in dicating that the structural transformation and the grain growth induce the defe ct changes occurring at the interfaces with different shapes and sizes.
基金Project supported by the Fundamental Research Funds for Central Universitiesthe National Natural Science Foundation of China(51101007)the National Basic Research Program of China(973Program)(2010CB934602)
文摘High-performance α-Fe/Pr2FelnB-type nanocomposite magnets based on the compositions of PrsFes6B6 microalloyed with Co, Nb and C were fabricated by direct melt spinning. The coercivity was greatly improved from 5.5 kOe for the Pr8Fe86B6 ribbons to 7.4 kOe for the Pr8Fe85NbB5C ribbons. The balanced high coercivity and remanence were obtained in Pr8Fe75Co10NbB5C ribbons due to the Co substitution for Fe, which led to the significant improvement of magnetic properties in these ribbons. A remanence ratio of 0.82, a coercive field of 6.6 kOe and a maximum energy product of 26.2 MGOe in melt-sptm Pr8Fe75Co10NbB5C ribbons were ob- tained at room temperature.
