Skip to main content
SpringerLink
Log in

Formation of the Face-Centered Cubic (FCC)-NdO x Phase at Nd/Nd-Fe-B Interface: A First-Principles Modeling

  • Published:
JOM Aims and scope Submit manuscript

Abstract

The development of advanced Nd-Fe-B permanent magnet materials with high coercivity draws much attention to the relation between coercivity and microstructure at the grain boundaries of the magnets. A disordered face-centered cubic (fcc)-NdO x phase formed at the interface of Nd/Nd-Fe-B is observed, and it is believed to take an important role in coercivity generation. To have a thorough understanding of the formation mechanism of this particular oxide and its relation to the surface coercivity, a ground state analysis for whole oxygen concentration in Nd-O has been performed by combining the LSDA + U and the cluster expansion method. Systematic calculations revealed that a sequent fcc-based structure formed by introducing oxygen vacancies into NdO is stable in almost all the 0–50% oxygen concentration range, whereas in a series of hexagonal close-packed (hcp)-based structures developed from hP5-Nd2O3 no stable structure is observed, which coincides with the experimental measurement very well. A further analysis of formation energies and relevant changes in electronic structures of single oxygen vacancy in various structures revealed the insight of such fcc-based phase formation and further explained the relation between the phase stability and coercivity.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

  1. S. Hirosawa, T. Fukagawa, and T. Maki, Phys. Status Solidi C 4, 4606 (2007).

    Article  Google Scholar 

  2. W. Mo, L. Zhang, and Q. Liu, Scr. Mater. 59, 179 (2008).

    Article  Google Scholar 

  3. T. Fukagawa and S. Hirosawa, J. Appl. Phys. 104, 013911 (2008).

    Article  Google Scholar 

  4. T. Fukagawa and S. Hirosawa, Scr. Mater. 59, 183 (2008).

    Article  Google Scholar 

  5. T. Fukagawa, S. Hirosawa, T. Ohkubo, and K. Hono, J. Appl. Phys. 105, 07A724 (2009).

    Article  Google Scholar 

  6. Y. Chen, S. Hirosawa, and S. Iwata, Mater. Sci. Forum 654, 1674 (2010).

    Article  Google Scholar 

  7. G. Kresse and D. Joubert, Phys. Rev. B 59, 1758 (1999).

    Article  Google Scholar 

  8. G. Kresse, VASP, Vienna Ab Initio Simulation Package (2004). http://www.vasp.at.

  9. P.E. Blochl, Phys. Rev. B 50, 17953 (1994).

    Article  Google Scholar 

  10. P. Perdew, Phys. Rev. B 46, 6671 (1992).

    Article  Google Scholar 

  11. A.I. Liechtenstein, V.I. Anisimov, and J. Zaane, Phys. Rev. B 52, R5467 (1995).

    Article  Google Scholar 

  12. A. Shankar, D.P. Rai, Sandeep, and R.K. Thapa, J. Semicond. 33, 082001 (2012).

    Article  Google Scholar 

  13. W. Connolly and A.R. Williams, Phys. Rev. B 27, 5169 (1983).

    Article  Google Scholar 

  14. Axel van de Walle, CALPHAD 33, 266 (2009).

    Article  Google Scholar 

  15. M. Matsuura, N. Tezuka, and S. Sugimoto, Paper presented at the Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications (Nagasaki, Japan, September 2012), P3-016.

  16. M. Matsuura (Doctoral dissertation, Graduate school of Engineering, Tohoku University, Japan, 2012).

  17. G. Hrkac, T.G. Woodcock, and C. Freeman, Appl. Phys. Lett. 97, 232511 (2010).

    Article  Google Scholar 

Download references

Acknowledgements

This work is supported by the Elements Strategy Initiative Center for Magnetic Materials (ESICMM) under the outsourcing project of MEXT. The authors would like to express their sincere thanks to the crew of Center for Computational Materials Science of the Institute for Materials Research, Tohoku University, for their continuous support of the SR11000/SR16000 supercomputing facilities.

Author information

Authors and Affiliations

  1. Department of Nanomechanics, School of Engineering, Tohoku University, 6-6-01 Aramakiaoba, Aoba-ku, Sendai, 980-8579, Japan

    Ying Chen & Arkapol Saengdeejing

  2. Department of Materials Science, School of Engineering, Tohoku University, 6-6-01 Aramakiaoba, Aoba-ku, Sendai, 980-8579, Japan

    Masashi Matsuura & Satoshi Sugimoto

Authors
  1. Ying Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Arkapol Saengdeejing
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Masashi Matsuura
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Satoshi Sugimoto
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Ying Chen.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chen, Y., Saengdeejing, A., Matsuura, M. et al. Formation of the Face-Centered Cubic (FCC)-NdO x Phase at Nd/Nd-Fe-B Interface: A First-Principles Modeling. JOM 66, 1133–1137 (2014). https://doi.org/10.1007/s11837-014-1004-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11837-014-1004-1

Keywords

Search

Navigation