Improved magnetic properties and thermal stabilities of Pr-Nd-Fe-B sintered magnets by Hf addition
Qingzheng Jiang,
Weikai Lei,
Qingwen Zeng,
Qichen Quan,
Lili Zhang,
Renhui Liu,
Xianjun Hu,
Lunke He,
Zhiqi Qi,
Zhihua Ju,
Minglong Zhong,
Shengcan Ma,
Zhenchen Zhong
Affiliations
Qingzheng Jiang
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Weikai Lei
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Qingwen Zeng
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Qichen Quan
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Lili Zhang
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Renhui Liu
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Xianjun Hu
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Lunke He
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Shengcan Ma
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Zhenchen Zhong
Jiangxi Key Laboratory for Rare Earth Magnetic Materials and Devices & Institute for Rare Earth Magnetic Materials and Devices (IREMMD), Jiangxi University of Science and Technology, Ganzhou 341000, P.R.China
Nd2Fe14B-type permanent magnets have been widely applied in various fields such as wind power, voice coil motors, and medical instruments. The large temperature dependence of coercivity, however, limits their further applications. We have systematically investigated the magnetic properties, thermal stabilities and coercivity mechanisms of the (Pr0.2Nd0.8)13Fe81-xB6Hfx (x=0, 0.5) nanocrystalline magnets fabricated by a spark plasma sintering (SPS) technique. The results indicate that the influence of Hf addition is significant on magnetic properties and thermal stabilities of the (PrNd)2Fe14B-type sintered magnets. It is shown that the sample with x = 0.5 at 300 K has much higher coercivity and remanent magnetization than those counterparts without Hf. The temperature coefficients of remanence (α) and coercivity (β) of the (Pr0.2Nd0.8)13Fe81-xB6Hfx magnets are improved significantly from -0.23 %/K, -0.57 %/K for the sample at x = 0 to -0.17 %/K, -0.49 %/K for the sample at x = 0.5 in the temperature range of 300-400 K. Furthermore, it is found out that the domain wall pinning mechanism is more likely responsible for enhancing the coercivity of the (Pr0.2Nd0.8)13Fe81-xB6Hfx magnets.
