Effects of size and surface anisotropy on thermal magnetization and hysteresis in the magnetic clusters

Solid and Condensed State Physics


Based on Monte Carlo simulation, the spin configurations, thermal magnetization and hysteresis loops of the clusters coated by the surface shell with radial anisotropy are studied. Interestingly, a new multidomain containing a few of subdomains whose easy directions are along those of the configurational anisotropy, a magnetization curve in steps and a first order phase transition from the single domain to the multidomain in the thermal and field magnetization processes, are found, which is as a result of the interplay of the configurational anisotropy, the size effect, the surface anisotropy, the applied field and the thermal fluctuation. In this first order transition, we find a critical temperature, a critical surface anisotropy and a critical size. The simulated temperature dependence of the coercivity of the cluster with the surface anisotropy can be fitted by Hc (T)=Hc (0)(1-CαTα) with low value of α, which explains well the experimental results of the nanoparticles. Moreover, it is found that the hysteresis loops and coercivity are strongly affected by the cluster size and the thickness of the surface layer.


75.75.+a Magnetic properties of nanostructures 75.40.Mg Numerical simulation studies 75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects 75.60.Jk Magnetization reversal mechanisms 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. R.H. Kodama, A.E. Berkowitz, Phys. Rev. Lett. 77, 394 (1996); R.H. Kodama, A.E. Berkowitz, J. Appl. Phys. 81, 5552 (1997); R.H. Kodama, A.E. Berkowitz, Phys. Rev. B 59, 6321 (1999) CrossRefADSGoogle Scholar
  2. K. Haneda, Can. J. Phys. 65, 1233 (1987) ADSGoogle Scholar
  3. J.M.D. Coey, Phys. Rev. Lett. 27, 1140 (1971) CrossRefADSGoogle Scholar
  4. P. Prene et al., Hyperfine Interactions 93, 1049 (1994) Google Scholar
  5. J.P. Chen, C.M. Sorensen, K.J. Klabunde, G.C. Hadjipanayis, Phys. Rev. B 51, 11527 (1995) CrossRefADSGoogle Scholar
  6. R.D. Zysler, H. Romero, C.A. Ramos, E. De Biasi, D. Fiorani, J. Magn. Magn. Mater. 266, 233 (2003) CrossRefADSGoogle Scholar
  7. E. De Biasi, C.A. Ramos, R.D. Zysler, Phys. Rev. B 65, 233 (2003) Google Scholar
  8. B. Heinrich, B.K. Urguhart, A.S. Arrott, J.F. Cochran, K. Myrtle, S.T. Purcell, Phys. Rev. Lett. 59, 2464 (1987) CrossRefGoogle Scholar
  9. S.T. Purcell, B. Heinrich, A.S. Arrott, J. Appl. Phys. 64, 5337 (1988) CrossRefADSGoogle Scholar
  10. G.S. Gay, R. Richter, Phys. Rev. Lett. 56, 2728 (1986) CrossRefADSGoogle Scholar
  11. J.P. Chen, C.M. Sorensen, K.J. Klabunde, G.C. Hadjipanayis, J. Appl. Phys. 76, 6316 (1994) CrossRefADSGoogle Scholar
  12. F. Bodker, S. Morup, S. Linderoth, Phys. Rev. Lett. 72, 282 (1994) CrossRefADSGoogle Scholar
  13. T. Kaneyoshi, J. Phys.: Condens. Matter 3, 4497 (1991) CrossRefADSGoogle Scholar
  14. D.A. Dimitrov, G.M. Wysin, Phys. Rev. B 51, 11947 (1995) CrossRefADSGoogle Scholar
  15. Per-Anker Lindgard, P.V. Hendriksen, Phys. Rev. B 49, 12291 (1994) CrossRefADSGoogle Scholar
  16. K.B. Urquhart, B. Heinrich, J.F. Cochran, A.S. Arrot, K. Myrtle, J. Appl. Phys. 64, 5334 (1988) CrossRefADSGoogle Scholar
  17. Z.S. Shan, D.J. Sellmyer, S.S. Jaswal, Y.J. Wang, J.X. Shen, Phys. Rev. Lett. 63, 449 (1989) CrossRefADSGoogle Scholar
  18. M. Dimian, H. Kachkachi, J. Appl. Phys. 91, 7625 (2002) CrossRefADSGoogle Scholar
  19. Y. Labaye, O. Crisan, L. Berger, J.M. Greneche, J.M.D. Coey, J. Appl. Phys. 91, 8715 (2002) CrossRefADSGoogle Scholar
  20. H. Kachkachi, M. Dimian, Phys. Rev. B 66, 174419 (2002) CrossRefADSGoogle Scholar
  21. O. Iglesias, A. Labarta, Physica B 343, 286 (2004) MathSciNetCrossRefADSGoogle Scholar
  22. L. Hernandez, C. Pinettes, J. Magn. Magn. Mater. 295, 82 (2005) CrossRefADSGoogle Scholar
  23. D.A. Dimitrov, G.M. Wysin, Phys. Rev. B 50, 3077 (1994) CrossRefADSGoogle Scholar
  24. Zhigao Huang, Zhigao Chen, Fengming Zhang, Youwei Du, Eur. Phys. J. B 37, 177 (2004) CrossRefADSGoogle Scholar
  25. Zhigao Huang, Youwei Du, Phys. Lett. A 300, 641 (2002) CrossRefGoogle Scholar
  26. S.T. Chui, T. De-Cheng, J. Appl. Phys. 78, 3965 (1995) CrossRefADSGoogle Scholar
  27. X. Zianni, K.N. Trohidou, J. Appl. Phys. 85, 1050 (1999) CrossRefADSGoogle Scholar
  28. K. Binder, D.W. Heermann, Monte Carlo Simulation in Statistical Physics (Springer, Berlin, 1992) Google Scholar
  29. M.E. Schabes, H.N. Bertram, J. Appl. Phys. 64, 1347 (1988) CrossRefADSGoogle Scholar
  30. L. Torres, E. Martinez, L. Lopez-Diaz, J. Iniguez, J. Appl. Phys. 89, 7585 (2001) CrossRefADSGoogle Scholar
  31. R.P. Cowburn, J. Phys. D: Appl. Phys. 33, R1 (2000) Google Scholar
  32. R.P. Cowburn, A.O. Adeyeye, M.E. Welland, Phys. Rev. Lett. 81, 5414(1998) CrossRefADSGoogle Scholar
  33. H. Pfeiffer, W. Schuppel, Phys. Status Solidi A 119, 259 (1990) Google Scholar
  34. J. Garcia-Otero, A.J. garcia-Bastida, J. Rivas, J. Magn. Magn. Mater. 189, 377 (1998) CrossRefADSGoogle Scholar
  35. K.N. Trohidou, C.M. Soukoulis, A. Kostikas, G. Hadjipanayis, J. Magn. Magn. Mater. 104–107, 1587 (1992) Google Scholar
  36. S.M. Stinnett, J.W. Harrell, A.F. Khapikov, W.D. Doyle, IEEE Trans. on Magn. 36, 148 (2000) CrossRefGoogle Scholar
  37. A. Ajan, E.N. Abarra, B.R. Acharya, A. Inomata, I. Okamoto, M. Shinohara, Appl. Phys. Lett. 82, 1075 (2003) CrossRefADSGoogle Scholar
  38. S.U. Jen, C.Y. Lee, Y.D. Yao, J. Magn. Magn. Mater. 96, 82 (1991) CrossRefADSGoogle Scholar
  39. C. Johansson, T. Aklint, M. Hanson, M. Andersson, N. Tarras-Wahlberg, E. Olsson, B. Kalska, R. Wappling, A. Rosen, Nanostructureed Materials 12, 287 (1999) MathSciNetCrossRefGoogle Scholar
  40. B. Martinez, A. Roig, X. Obradors, E. Molins, J. Appl. Phys. 79, 2580 (1996) CrossRefADSGoogle Scholar
  41. B.N. Bhowmik, R. Ranganathan, J. Magn. Magn. Mater. 248, 101 (2002) CrossRefADSGoogle Scholar

Copyright information

© EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006

Authors and Affiliations

  • Z. Huang
    • 1
  • Z. Chen
    • 1
  • S. Li
    • 1
  • Q. Feng
    • 1
  • F. Zhang
    • 2
  • Y. Du
    • 2
  1. 1.Department of PhysicsFujian Normal UniversityFuzhouP.R. China
  2. 2.National Laboratory of Solid State Microstructures, Nanjing UniversityNanjingP.R. China

Personalised recommendations