MM_(33)Fe_(66)B(MM=La, Ce, Pr, Nd) alloys(mass ratio) were prepared by induction melting and heat-treated at 1353 K for 24 h to produce homogeneous MM_2Fe_(14) B phase. The phase structure and element distri...MM_(33)Fe_(66)B(MM=La, Ce, Pr, Nd) alloys(mass ratio) were prepared by induction melting and heat-treated at 1353 K for 24 h to produce homogeneous MM_2Fe_(14) B phase. The phase structure and element distribution of the alloys were analyzed by X-ray diffraction(XRD) and scanning electron microscope(SEM). The alloys were applied ball milling to obtain powders with good size distribution and then magnetic aligned in a static magnetic field of 2 T for 4 h, in order to achieve the intrinsic magnetic properties by vibrating sample magnetometer(VSM). XRD results showed that the alloys were composed of the single 2:14:1 main phase and RE-rich phase, which was similar to Nd_2Fe_(14)B structure. Magnetic measurements showed that the saturation magnetization(Ms) and anisotropy field(HA) of the MM_(33)Fe_(66)B alloy were 11.3 k Gs and 48.4 k Oe, respectively, demonstrating its good potential as permanent magnets. The Curie temperature of the MM_(33)Fe_(66)B alloy was determined as 502.9 K by magnetization-temperature curves. Microstructure observation showed that Nd and Pr were mainly in the 2:14:1 ferromagnetic phase, while La and Ce prefered to aggregate in the RE-rich grain boundary phase, which is beneficial to fabricating(Pr, Nd, MM)_2Fe_(14)B magnets with good magnetic properties.展开更多
基金Project supported by the National High Technology Research and Development Program of China(2012AA063201)National Natural Science Foundation of China(51371002+2 种基金51331003)International S&T Cooperation Program of China(2015DFG52020)the 2011 Cooperative Innovation Center of Beijing University of Technology
文摘MM_(33)Fe_(66)B(MM=La, Ce, Pr, Nd) alloys(mass ratio) were prepared by induction melting and heat-treated at 1353 K for 24 h to produce homogeneous MM_2Fe_(14) B phase. The phase structure and element distribution of the alloys were analyzed by X-ray diffraction(XRD) and scanning electron microscope(SEM). The alloys were applied ball milling to obtain powders with good size distribution and then magnetic aligned in a static magnetic field of 2 T for 4 h, in order to achieve the intrinsic magnetic properties by vibrating sample magnetometer(VSM). XRD results showed that the alloys were composed of the single 2:14:1 main phase and RE-rich phase, which was similar to Nd_2Fe_(14)B structure. Magnetic measurements showed that the saturation magnetization(Ms) and anisotropy field(HA) of the MM_(33)Fe_(66)B alloy were 11.3 k Gs and 48.4 k Oe, respectively, demonstrating its good potential as permanent magnets. The Curie temperature of the MM_(33)Fe_(66)B alloy was determined as 502.9 K by magnetization-temperature curves. Microstructure observation showed that Nd and Pr were mainly in the 2:14:1 ferromagnetic phase, while La and Ce prefered to aggregate in the RE-rich grain boundary phase, which is beneficial to fabricating(Pr, Nd, MM)_2Fe_(14)B magnets with good magnetic properties.