Rare earth permanent magnet nanostructures have attracted intensive interest recently due to the increasing demand for integrated and miniaturized devices.As a typical example,hard magnetic Nd_(2)Fe_(14)B-based nanost...Rare earth permanent magnet nanostructures have attracted intensive interest recently due to the increasing demand for integrated and miniaturized devices.As a typical example,hard magnetic Nd_(2)Fe_(14)B-based nanostructures with desired coercivity have been developed by a reduction–diffusion process and the Nd-rich phase is supposed to be essential to optimize the magnetic properties,whereas the identification and role of the Nd-rich phase have not been addressed so far.Herein,Nd_(2)Fe_(14)B-based nanostructures with different Nd-rich phase contents,Nd_(15)Fe_(77)B_(8) and Nd_(14.2)Fe_(78.6)B_(7.2),are rationally prepared by a reduction–diffusion process.The coercivity of Nd_(15)Fe_(77)B_(8) can reach 5 kOe,which is higher than that of Nd_(14.2)Fe_(78.6)B_(7.2) of 3.2 kOe.First-order-reversal-curve (FORC) analysis confirms the amorphous paramagnetic Nd-rich phase as pinning centers and reveals magnetic interactions and magnetic domain nature in the two nanostructures.The increase of the Nd-rich phase optimizes microstructures and magnetic interactions,responsible for higher coercivity.This work points out the relationship between the Nd-rich phase,magnetic interactions,microstructures,and magnetic properties,and could usher in new ways of fabricating advanced permanent magnetic nanostructures.展开更多
基金supported by the National Natural Science Foundation of China(51590882,51631001 and 51672010)the National Key R&D Program of China(2017YFA0206301).
文摘Rare earth permanent magnet nanostructures have attracted intensive interest recently due to the increasing demand for integrated and miniaturized devices.As a typical example,hard magnetic Nd_(2)Fe_(14)B-based nanostructures with desired coercivity have been developed by a reduction–diffusion process and the Nd-rich phase is supposed to be essential to optimize the magnetic properties,whereas the identification and role of the Nd-rich phase have not been addressed so far.Herein,Nd_(2)Fe_(14)B-based nanostructures with different Nd-rich phase contents,Nd_(15)Fe_(77)B_(8) and Nd_(14.2)Fe_(78.6)B_(7.2),are rationally prepared by a reduction–diffusion process.The coercivity of Nd_(15)Fe_(77)B_(8) can reach 5 kOe,which is higher than that of Nd_(14.2)Fe_(78.6)B_(7.2) of 3.2 kOe.First-order-reversal-curve (FORC) analysis confirms the amorphous paramagnetic Nd-rich phase as pinning centers and reveals magnetic interactions and magnetic domain nature in the two nanostructures.The increase of the Nd-rich phase optimizes microstructures and magnetic interactions,responsible for higher coercivity.This work points out the relationship between the Nd-rich phase,magnetic interactions,microstructures,and magnetic properties,and could usher in new ways of fabricating advanced permanent magnetic nanostructures.
