摘要
The isotropic nanocrystalline[(PrNd)0.8MM0.2]29.8Fe68.7Al0.1Cu0.12Co0.88B magnets(MM:mischmetal)were prepared by single-main phase and double-main phase methods using spark plasma sintering(SPS).Melt-spinning method was used to prepare initial powder and avoid component deviations caused by longtime ball milling.The magnetic properties of the magnet prepared by double-main phase method(called double-main phase magnet,DMP magnet)are remanence of Br=0.75 T,intrinsic coercivity of Hcj=909.83 kA·m-1,maximum magnetic energy product of(BH)max=95.48 kJ·m-3,which are better than those of the magnet prepared by single-main phase method(called singlemain phase magnet,SMP magnet).The diffraction peaks of the main phase of DMP magnet split in X-ray diffractometer(XRD)pattern,indicating that R2 Fe14B phases with different distributions of La/Ce elements exist in the magnet.This speculation is confirmed by transmission electron microscopy(TEM)observation.The La/Ce-rich main phase and La/Celean main phase are present in DMP magnets.The heterogeneity of rare earth elements suppresses the magnetic dilution effect in DMP magnet,and the magnetic properties are improved.Though the DMP magnet contains different main phases,it presents unitary Curie temperature(TC)of 577 K,which is higher than that of SMP magnet.This result suggests that the TC of the magnets can be promoted by double-main phase method and SPS.
The isotropic nanocrystalline [（PrNd）0.8MM0.2]29.8Fe68.7Al0.1Cu0.12Co0.88B magnets（MM:mischmetal） were prepared by single-main phase and double-main phase methods using spark plasma sintering（SPS）.Melt-spinning method was used to prepare initial powder and avoid component deviations caused by longtime ball milling.The magnetic properties of the magnet prepared by double-main phase method（called double-main phase magnet,DMP magnet） are remanence of Br=0.75 T,intrinsic coercivity of Hcj=909.83 kA·m-1,maximum magnetic energy product of（BH）max=95.48 kJ·m-3,which are better than those of the magnet prepared by single-main phase method（called singlemain phase magnet,SMP magnet）.The diffraction peaks of the main phase of DMP magnet split in X-ray diffractometer（XRD） pattern,indicating that R2 Fe14B phases with different distributions of La/Ce elements exist in the magnet.This speculation is confirmed by transmission electron microscopy（TEM） observation.The La/Ce-rich main phase and La/Celean main phase are present in DMP magnets.The heterogeneity of rare earth elements suppresses the magnetic dilution effect in DMP magnet,and the magnetic properties are improved.Though the DMP magnet contains different main phases,it presents unitary Curie temperature（TC） of 577 K,which is higher than that of SMP magnet.This result suggests that the TC of the magnets can be promoted by double-main phase method and SPS.
基金
financially supported by the National Key Research and Development Program of China(No.2016YFB0700903)
the National Natural Science Foundation of China(Nos.51571064 and 51571126).
作者简介
Ming-Gang Zhu,e-mail:mgzhu@sina.com;Correspondence to:Xue-Feng Zhang,e-mail:xuefeng367@163.com
