J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (9): 1877-1885.DOI: 10.1016/j.jmst.2019.05.007

• Orginal Article • Previous Articles     Next Articles

Improving the hard magnetic properties by intragrain pinning for Ta doped nanocrystalline Ce-Fe-B alloys

J.S. Zhanga, W. Lia, X.F. Liaoa, H.Y. Yua, L.Z. Zhaoab, H.X. Zenga, D.R. Penga, Z.W. Liua*()   

  1. a School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China
    b Innovative Center for Advanced Materials (ICAM), Hangzhou Dianzi University, Hangzhou, 310012, China
  • Received:2019-01-31 Revised:2019-02-03 Accepted:2019-03-08 Online:2019-09-20 Published:2019-07-26
  • Contact: Liu Z.W.
  • About author:

    1 These authors contributed equally to this work.


To develop Ce based permanent magnets with high performance/cost ratio, Ta doping is was employed to enhance the magnetic performance of Ce-Fe-B alloys. For melt spun Ce17Fe78-xTaxB6 (x = 0-1) alloys, the coercivity Hc increases from 439 to 553 kA/m with increasing x value from 0 to 0.75. Microstructure characterizations indicate that Ta doping is helpful for grain refinement. A second phase of TaB2 is observed in Ce17Fe77.25Ta0.75B6 alloy, which acts as the pinning center of the magnetic domains, resulting in the change of coercivity mechanism from nucleation type to nucleation + pinning type. The micromagnetic simulation confirms that non-magnetic particles within hard magnetic phase can increase the demagnetization field around them and it is crucial for preventing the further magnetization reverse by pinning effect. Take the advantage of Ta doping for enhancing the coercivity, Ce content of Ce-Fe-B alloy can be further cut down to increase the remanence Jr due to the reduced volume fraction of CeFe2 phase and increased Fe/Ce ratio. As a result, a good combination of magnetic properties with Hc = 514 kA/m, Jr = 0.49 T, and the maximum energy product (BH)max = 36 kJ/m3 have been obtained in Ce15Fe79.25Ta0.75B6 alloy. It is expected that the present work can serve as a useful reference for designing new permanent magnetic materials with low-cost.

Key words: Melt-spinning, Permanent magnets, Second phase, Coercivity mechanism, Thermal stability