Exchange-Coupled Nanocomposite Permanent Magnets

  • J.P. Liu


Exchange-coupled nanocomposite magnets are a new type of permanent magnetic materials. Large amounts of theoretical and experimental research have been carried out in the past two decades in understanding the inter-phase exchange interactions and in processing bulk nanocomposite magnets with enhanced energy products. This chapter reviews recent advancements in both the fundamental research and the materials processing technologies. Details in the new findings about the effects of soft phase properties and interface conditions on the hard/soft phase exchange interactions are presented. Various methods for characterizing the inter-phase exchange coupling are reviewed. In materials processing aspects, the development of the bottom-up approaches is discussed. Novel methodology for nanoparticle synthesis including the salt-matrix annealing and surfactant-assisted ball milling is described. Unconventional compaction techniques including warm compaction and dynamic compaction are recommended because they can be used to retain the desired nanoscale morphology for effective exchange coupling in the nanocomposites. At the end of this chapter, perspectives on fabrication of anisotropic nanocomposite magnets are given.


Exchange Coupling Nanocomposite Magnet Dynamic Compaction FePt Nanoparticles Explosive Compaction 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



First I would like to thank my former promoter and colleague Prof. D.J. Sellmyer (one of the editors of this book) who guided me to enter this research area in 1995. I would also like to thank my students, postdoctoral researchers, and collaborators who have contributed directly to the work reviewed in this chapter: H. Zeng, T. S. Vedantam, B. Altuncevahir, N. Poudyal, V. Chakka, K.E. Elkins, V. Nandwana, K.H. Chen, Z.Q. Jin, C.-b Rong, G. Chaubey, Y. Li, K. Yano, D. Li, Y. Wang, M. Yue, T. Black, Q. Zhang, D. Wu, Z.J. Guo, Y. Choi, J.S. Jiang, S.D. Bader, S. Saha, J.A. Barnard, W. Sofa, S.G. Sankar, G. Zangari, C. O’Connor, M.-h Yu, A.J. Zambano, I. Takeuchi, S.S. Yan, B.Z. Cui, K. Han, H. Garmestani, H. Schneider-Muntau, J. Crow, M. Chen, Y. Hou, S. Sun, K. Gallagher, S.-F. Cheng, J. Li, Y. Ding, Y. Liu, Y. Zhang, M.J. Kramer, C.D. Dai, N.N. Thadhani, and Z.L. Wang. This work has been supported in part by US DoD/DARPA through ARO under grant DAAD 19-03-1-0038 and DoD/MURI grant N00014-05-1-0497. Dr. V. Browning and Dr. J. Prater are highly appreciated for their long-term support to this effort.


  1. 1.
    R. Coehoorn, D.B. de Mooij and C. de Waard, J. Magn. Magn. Mat. 80 (1989) 101.CrossRefGoogle Scholar
  2. 2.
    E. F. Kneller and R. Hawig, IEEE Trans. Magn. 27 (1991) 3588.CrossRefGoogle Scholar
  3. 3.
    A. Manaf, R.A. Buckley and H.A. Davis, J. Magn. Magn. Mat. 128 (1993) 302.CrossRefGoogle Scholar
  4. 4.
    L. Withanawasam, G.C. Hadjipanayis and R.F. Krause, J. Appl. Phys. 76 (1994) 6646.CrossRefGoogle Scholar
  5. 5.
    J. Ding, P.G. McCormick and R. Street, JMMM, 124 (1993) LI.Google Scholar
  6. 6.
    O'Donnell, C. Kuhrt and J.M.D. Coey, JAP, 76 (1994) 7068.Google Scholar
  7. 7.
    I.A. Al-Omari and D.J. Sellmyer, Phys. Rev. B 52 (1995) 3441.CrossRefGoogle Scholar
  8. 8.
    L.H. Lewis, D.O. Welch and V. Panchanathan, J. Magn. Magn. Mat., 175 (1997) 275.CrossRefGoogle Scholar
  9. 9.
    M. Ddahlgren, R. Grossinger, E. de Morais, S. Gama, G. Mendoza, J.F. Liu and H.A. Davis, IEEE Trans. Magn., 33 (1997) 3895.CrossRefGoogle Scholar
  10. 10.
    J.P. Liu, C.P. Luo, Y. Liu and D.J. Sellmyer, Appl. Phys. Lett. 72 (1998) 483–485.CrossRefGoogle Scholar
  11. 11.
    X. Rui, J. E. Shield, Z. Sun, Y. Xu and D. J. Sellmyer, Appl. Phys. Lett. 89 (2006) 122509.CrossRefGoogle Scholar
  12. 12.
    H. Zeng, J. Li, J. P. Liu, Z. L. Wang and S.H. Sun, Nature, 420 (2002) 395–398.CrossRefGoogle Scholar
  13. 13.
    K.H. Chen, Z.Q. Jin, J. Li, G. Kennedy, H. Zeng, S.-F. Cheng, Z.L. Wang, N. N. Thadhani and J.P. Liu, J. Appl. Phys. 96 (2004), 1276–1278.CrossRefGoogle Scholar
  14. 14.
    C.B. Rong, V. Nandwana, N. Poudyal, J.P. Liu, M.E. Kozlov, R.H. Baughman, Y. Ding and Z. L. Wang, J. Appl. Phys., 101 (2007) 023908.CrossRefGoogle Scholar
  15. 15.
    C. Rong, Y.Z. Liu, M. Kramer and J.P. Liu, in preparationGoogle Scholar
  16. 16.
    T. Schrefl, H. Kronmüller and J. Fidler, J. Magn. Magn. Mater. 127 (1993) L273.CrossRefGoogle Scholar
  17. 17.
    R. Skomski and J.M.D. Coey, Phys. Rev. B 48 (1993) 15812.CrossRefGoogle Scholar
  18. 18.
    R.F. Sabiryanov and S.S. Jaswal, J. Magn. Magn. Mater., 177–181(1998a) 989.CrossRefGoogle Scholar
  19. 19.
    R.F. Sabiryanov and S.S. Jaswal, Phys. Rev. B 58(1998b) 12071.CrossRefGoogle Scholar
  20. 20.
    H. Kronmüller, R. Fisher, M. Bachmann and T. Leinewber, J. Magn. Magn. Mater. 203 (1999) 12.CrossRefGoogle Scholar
  21. 21.
    Z.S. Shan, J.P. Liu, V.M. Chkka, H. Zeng and J.S. Jiang, IEEE Trans on Magn, 38 (2002) 2907.CrossRefGoogle Scholar
  22. 22.
    Z.J. Guo, J.S. Jiang, J.E. Pearson, S.D. Bader and J.P. Liu, Appl. Phys. Lett., 81 (2002) 2029.CrossRefGoogle Scholar
  23. 23.
    G. Asti, M. Solzi, M. Ghidini and F.M. Neri, Phys. Rev. B 69 (2004) 174401.CrossRefGoogle Scholar
  24. 24.
    A.J. Zambano, H. Oguchi, I. Takeuchi, Y. Choi, J.S. Jiang, J.P. Liu, S.E. Lofland, D. Josell and L.A. Bendersky, Phys. Rev. B 75 (2007) 144429-1-7.CrossRefGoogle Scholar
  25. 25.
    J.P. Liu, Y. Liu, R. Skomski and D.J. Sellmyer, IEEE Trans on Magn. 35 (1999) 3241.CrossRefGoogle Scholar
  26. 26.
    J.S. Jiang, J.E. Pearson, Z.Y. Liu, B. Kabius, S. Trasobares, D.J. Miller, S.D. Bader, D.R. Lee, D. Haskel, G. Srajer and J.P. Liu, Appl. phys. Lett. 85(2004) 5293.CrossRefGoogle Scholar
  27. 27.
    Y. Choi, J.S. Jiang, Y. Ding, R.A. Rosenberg, J.E. Pearson, S.D. Bader, A. Zambano, M. Murakami, I. Takeuchi, Z.L. Wang and J.P. Liu, Phys. Rev. B 75 (2007) 104432-1-6.CrossRefGoogle Scholar
  28. 28.
    D.X. Wu, Q.M. Zhang, J.P. Liu, D.W. Yuan and R.Q. Wu, Appl. Phys. Lett. 92 (2008) 052503.CrossRefGoogle Scholar
  29. 29.
    J.P. Liu, Y. Liu and D.J. Sellmyer, J. Appl. Phys. 83 (1998) 6608.CrossRefGoogle Scholar
  30. 30.
    G.P. Zhao and X.L. Wang, Phys. Rev. B 74 (2006) 012409.CrossRefGoogle Scholar
  31. 31.
    G.P. Zhao, M.G. Zhao, H.S. Lim, Y.P. Feng, and C.K. Ong, Appl. Phys. Lett. 87 (2005) 162513.CrossRefGoogle Scholar
  32. 32.
    D.J. Craik and E.D. Isaac, Proc. Phys. Soc. 76 (1960) 160.CrossRefGoogle Scholar
  33. 33.
    D. Goll, M. Seeger and H. Kronmuller, J. Magn. Magn. Mater. 185 (1998) 49.CrossRefGoogle Scholar
  34. 34.
    J.P. Liu, R. Skomski, Y. Liu and D.J. Sellmyer, J. Appl. Phys. 87 (2000) 6740.CrossRefGoogle Scholar
  35. 35.
    K. Kang, L.H. Lewis, J.S. Jiang, and S.D. Bader, J. Appl. Phys. 98 (2005)113906.CrossRefGoogle Scholar
  36. 36.
    D.C. Crew, J. Kim, L.H. Lewis, and K. Barmak, J. Magn. Magn. Mater. 233 (2001) 257.CrossRefGoogle Scholar
  37. 37.
    Y. Choi, J.S. Jiang, J.E. Pearson, S.D. Bader and J. P. Liu, Appl. Phys. Lett. 91(2007) 022502.CrossRefGoogle Scholar
  38. 38.
    C.B. Rong, Y. Liu and J.P. Liu, Appl. Phys. Lett. 93 (2008) 042508.CrossRefGoogle Scholar
  39. 39.
    E.P. Wohlfarth, J. Appl. Phys. 29 (1958) 595.CrossRefGoogle Scholar
  40. 40.
    P.E. Kelly, K. O'Grady, P.I. Mayo and R.W. Chantrell, IEEE Trans. Magn. 25 (1989) 3881.CrossRefGoogle Scholar
  41. 41.
    G. Srajer, L.H. Lewis, S.D. Bader, A.J. Epstein, C.S. Fadley, E.E. Fullerton, A. Hoffmann, J.B. Kortright, K.M. Krishnan, S.A. Majetich, T.S. Rahman, C.A. Ross, M.B. Salamon, I.K. Schuller, T.C. Schulthess and J.Z. Sun, J. Magn. Magn. Mater. 307 (2006) 1.CrossRefGoogle Scholar
  42. 42.
    M.-h. Yu, J. Hattrick-Simpers, I. Takeuchi, J. Li, Z.L. Wang, S.E. Lofland, S. Tyagi, J.W. Freeland, D. Giubertoni, M. Bersani and M. Anderle, J. Appl. Phys. 98 (2005) 063908.CrossRefGoogle Scholar
  43. 43.
    J.E. Davies, O. Hellwig, E.E. Fullerton, J.S. Jiang, S.D. Bader, G.T. Zimanyi and K. Liu, Appl. Phys. Lett. 86 (2005) 262503.CrossRefGoogle Scholar
  44. 44.
    G.C. Hadjipanayis, J. Magn. Magn. Mater. 200 (1999) 373.CrossRefGoogle Scholar
  45. 45.
    D.H. Ping, K. Hono and S. Hirosawa, J. Appl. Phys. 83 (1998) 7769.CrossRefGoogle Scholar
  46. 46.
    Y. Gao, J.H. Zhu, Y.Q. Weng, E.B. Park, C.J. Yang, J. Magn. Magn. Mater. 191 (1999) 146.CrossRefGoogle Scholar
  47. 47.
    P.G. McCormick, W.F. Miao, P.A.I. Smith, J. Ding and R. Street, J. Appl. Phys. 83 (1998) 6256.CrossRefGoogle Scholar
  48. 48.
    Z.D. Zhang, W. Liu, X.K. Sun, X.G. Zhao, Q.F. Xiao, Y.C. Sui and T. Zhao, J. Magn. Magn. Mater. 184 (1998) 101.CrossRefGoogle Scholar
  49. 49.
    E.E. Fullerton, J.S. Jiang, C.H. Sowers, J.E. Pearson, and S.D. Bader, Appl. Phys. Lett., 72 (1998) 380.CrossRefGoogle Scholar
  50. 50.
    J.P. Liu, Y. Liu, Z.S. Shan and D.J. Sellmyer, IEEE Trans. Magn. 33 (1997) 3709.CrossRefGoogle Scholar
  51. 51.
    J.P. Liu, Y.Liu and D.J. Sellmyer, J. Appl. Phys. 83 (1998) 6608.CrossRefGoogle Scholar
  52. 52.
    J.P. Liu, Y. Liu, R. Skomski and D.J. Sellmyer, J. Appl. Phys. 85 (1999) 4812.CrossRefGoogle Scholar
  53. 53.
    S. Sun, C.B. Murray, D. Weller, L. Folks and A. Moser, Science 287 (2000) 1989.CrossRefGoogle Scholar
  54. 54.
    V. Nandwana, K.E. Elkins, N. Poudyal, G.S. Chaubey, K. Yano and J.P. Liu, J. Phys. Chem. C 111(2007) 4185.CrossRefGoogle Scholar
  55. 55.
    N. Poudyal, G.S. Chaubey, V. Nandwana, C.B. Rong, K. Yano and J.P. Liu, Nanotechnology 19 (2008) 355601.CrossRefGoogle Scholar
  56. 56.
    K. Elkins, D.R. Li, N. Poudyal, V. Nandwana, Z.Q. Jin, K.H. Chen and J. P. Liu, J. Phys. D: Appl. Phys. 38 (2005) 2306.CrossRefGoogle Scholar
  57. 57.
    C.B. Rong, D.R. Li, V. Nandwana, N. Poudyal, Y. Ding, Z.L. Wang, H. Zeng and J.P. Liu, Adv. Mater. 18 (2006) 2984.CrossRefGoogle Scholar
  58. 58.
    J.P. Liu, K. Elkins, D. Li, V. Nandwana and N. Poudyal, IEEE Trans on Magn. 42 (2006) 3036.CrossRefGoogle Scholar
  59. 59.
    K. Ono, Y. Kakefuda, R. Okuda, Y. Ishii, S. Kamimura, A. Kitamura and M. Oshima J. Appl. Phys. 91 (2002) 8480.CrossRefGoogle Scholar
  60. 60.
    H. Gu, B. Xu, J. Rao, R.K. Zheng, X.X. Zhang, K.K. Fung and C.Y. Wong, J. Appl. Phys. 93 (2003) 7589.CrossRefGoogle Scholar
  61. 61.
    X. Teng, H. Yang, J. Nanosci. Nanotechnol. 7 (2007) 356.Google Scholar
  62. 62.
    Y.L. Hou, Z.C. Xu, S. Peng, C.B. Rong, J. P. Liu and S.H. Sun, Adv. Mater., 19 (2007) 3349.CrossRefGoogle Scholar
  63. 63.
    V.M. Chakka, B. Altuncevahir, Z.Q. Jin, Y. Li and J. P. Liu, J. Appl. Phys. 99 (2006) 08E912.CrossRefGoogle Scholar
  64. 64.
    Y.P. Wang, Y. Li, C.B. Rong and J.P. Liu, Nanotechnology 18 (2007) 465701.CrossRefGoogle Scholar
  65. 65.
    X. Rui, J.E. Shield, Z.Sun, R. Skomski, Y.Xu, D.J. Sellmyer, M.J. Kramer and Y.Q. Wu, J. Magn. Magn. Mater. 320 (2008) 2576.CrossRefGoogle Scholar
  66. 66.
    J.S. Chen, C.Y. Tan and G.M. Chow, Nanotechnology 18 (2007) 435604.CrossRefGoogle Scholar
  67. 67.
    J.M. Qiu and J.P. Wang, Adv. Mater. 19 (2007) 1703.CrossRefGoogle Scholar
  68. 68.
    G.S. Chaubey, V. Nandwana, N. Poudyal, C.B. Rong, and J.P. Liu, Chem. Mater. 20 (2008) 475.CrossRefGoogle Scholar
  69. 69.
    V. Nandwana, G.S. Chaubey, K. Yano, C.B. Rong and J.P. Liu, J. Appl. Phys. 105 (2009) 014303.Google Scholar
  70. 70.
    H.G. Rutz, F.G. Hanejko and S.H. Luk, Met. Powder Rep. 49 (1994) 40.Google Scholar
  71. 71.
    G.E. Fougere, J.R. Weertman and R.W. Siegel, Nanostructured Mater. 5 (1995) 127.CrossRefGoogle Scholar
  72. 72.
    K. Kondoh, T. Takikawa and R. Watanabe, JJSPM, 47 (2000) 94.Google Scholar
  73. 73.
    N. Tamari, T. Tanaka, K. Tanaka, I. Kondoh, M. Kawahara and M. Tokita, J. Ceramic Soc. Jpn. 103 (1995) 740.CrossRefGoogle Scholar
  74. 74.
    H. Ono, IEEE Trans. Magn. 37 (2001) 2552.CrossRefGoogle Scholar
  75. 75.
    M. Yue, M. Tian, et al., Mater. Sci. Eng. B 131 (2006), 1–3, 18–21.CrossRefGoogle Scholar
  76. 76.
    C.B. Rong, V. Nandwana, N. Poudyal, J.P. Liu, T. Saito, Y.Q. Wu and M. J. Kramer, J. Appl. Phys. 101 (2007) 09K505.CrossRefGoogle Scholar
  77. 77.
    K.H. Chen, Z.Q. Jin, J. Li, G. Kennedy, H. Zeng, S.F. Cheng, Z.L. Wang, N.N. Thadhani, and J.P. Liu, J. Appl. Phys. 96 (2004) 1276.CrossRefGoogle Scholar
  78. 78.
    J. Li, Z.Q. Jin, J. P. Liu, Z. L. Wang, and N.N. Thadhani, Appl. phys. Lett. 85 (2004) 2223.CrossRefGoogle Scholar
  79. 79.
    C.D. Dai, D. Eakins, N. Thadhani and J.P. Liu, Appl. Phys. Lett. 90 (2007) 071911.CrossRefGoogle Scholar
  80. 80.
    Z.Q. Jin, N.N. Thadhani, M. McGill, Y. Ding, Z.L. Wang, M. Chen, H. Zeng, V.M. Chakka and J.P. Liu, J. Mater. Res. 20 (2005) 599.CrossRefGoogle Scholar
  81. 81.
    M. Sachan and S.A. Majjetich, IEEE Trans. On Magn. 41 (2005), 3874.CrossRefGoogle Scholar
  82. 82.
    M. Chen, J. Kim, J.P. Liu, H.Y. Fan and S.H. Sun, Synthesis of FePt Nanocubes and Their Oriented Self-Assembly, J. Am. Chem. Soc. 128 (2006) 7132.CrossRefGoogle Scholar
  83. 83.
    C.Wang, Y.H. Hou, J. Kim and S.H. Sun, Angew. Chem. Int. Ed. 46 (2007).Google Scholar
  84. 84.
    N. Poudyal, B. Altuncevahir, V. Chakkal, K.H. Chen, T.D. Black, J.P. Liu, Y. Ding and Z.L. Wang, J. Phys. D: Appl. Phys. 37 (2004) L45.CrossRefGoogle Scholar
  85. 85.
    N.H. Hai, N.M. Dempsey and D. Givord, J. Magn. Magn. Mater. 262 (2003) 353.CrossRefGoogle Scholar
  86. 86.
    B.Z. Cui, K. Han, D.S. Li, H. Garmestani, J.P. Liu, N.M. Dempsey and H.J. Schneider-Muntau, J. Appl. Phys. 100 (2006) 013902.CrossRefGoogle Scholar
  87. 87.
    S. Saha, A. Kulovits, W.A. Soffa, and J. A. Barnard, J. Appl. Phys. 97 (2005) 10F301.CrossRefGoogle Scholar
  88. 88.
    D. S. Li, H. Garmestani, Shi-shen Yan, M. Elkawni, M.B. Bacaltchuk, H.J. Schneider-Muntau, J.P. Liu, S. Saha and J.A. Barnard, J. Magn. Magn. Mater. 281 (2004) 272.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of Texas at ArlingtonArlingtonUSA

Personalised recommendations