Transition from ferromagnetism to superparamagnetism on the nanosecond time scale

Physical Review B - Condensed Matter and Materials Physics

Volumn 65, Issue 22, 2002, Pages 1-10

  Lopez Diaz, L ^a   Torres, L ^a   Moro, E ^b  

^a UNIVERSITY OF SALAMANCA   (Spain)

^b UNIVERSITY OF OXFORD   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 26344469498     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.65.224406     Document Type: Article

References (26)

1. W.T. Coffey, Adv. Chem. Phys. 103, 259 (1998). There are different ways to define the relaxation time. This paper presents a comprehensive review of the different definitions.
2. G. Bertotti, Hysteresis in Magnetism (Academic Press, San Diego, 1998).
3. R.H. Koch, G. Grinstein, G.A. Keefe, Y. Lu, P.L. Trouilloud, W.J. Gallagher, and S.S.P. Parkin, Phys. Rev. Lett. 84, 5419 (2000).
4. N.G. van Kampen, Stochastic Processes in Physics and Chemistry (North-Holland, Amsterdam, 1981).
5. D. Rodé, H.N. Bertram, and D.R. Fredkin, IEEE Trans. Magn. MAG-23, 2224 (1987).
6. W.T. Coffey, D.S.F. Crothers, Y.P. Kalmykov, E.S. Massawe, and J.T. Waldron, Phys. Rev. E 49, 1869 (1994).
7. J.L. Garcia-Palacios and F.J. Lazaro, Phys. Rev. B 58, 14 937 (1998).
8. E.D. Boerner and H.N. Bertram, IEEE Trans. Magn. 33, 3052 (1997).
9. K.Z. Zhang and D.R. Fredkin, J. Appl. Phys. 85, 5208 (1999).
10. G. Brown, M.A. Novotny, and P.A. Rikvold, J. Appl. Phys. 89, 7588 (2001).
11. L. Lopez-Diaz, E. Della Torre, and E. Moro, J. Appl. Phys. 85, 4367 (1999).
12. T. Schrefl, W. Scholz, D. Suess, and J. Fidler, IEEE Trans. Magn. 36, 3189 (2000).
13. W.T. Coffey, D.S.F. Crothers, J.L. Dormann, L.J. Geoghegan, Y.P. Kalmykov, J.T. Waldron, and A.W. Wickstead, J. Magn. Magn. Mater. 145, L263 (1995).
14. W.T. Coffey, D.S.F. Crothers, J.L. Dormann, L.J. Geoghegan, and E.C. Kennedy, J. Magn. Magn. Mater. 173, L219 (1997).
15. W.T. Coffey, D.S.F. Crothers, J.L. Dormann, Y.P. Kalmykov, and S.V. Titov, Phys. Rev. B 64, 012411 (2001).
16. J.L. Garcia-Palacios and P. Svedlindh, Phys. Rev. Lett. 85, 3724 (2000).
17. H. Risken, The Fokker-Planck Equation, 2nd ed. (Springer, Berlin, 1989).
18. J.L. Garcia-Palacios, Adv. Chem. Phys. 112, 1 (2000).
19. Strictly speaking, (formula presented) is only valid for ellipsoidal particles (in which case (formula presented) is diagonal when referred to the principal axes of the ellipsoid), since in any other case the demagnetizing field is not constant. However, the expression can be generalized to any uniformly magnetized body considering that (formula presented) is the average demagnetizing field inside the particle. A.J. Newell, W. Williams, and D.J. Dunlop, J. Geophys. Res., [Solid Earth] 98, 9551 (1993).
20. M.J. Donahue and R.D. McMichael, Physica B 233, 272 (1997).
21. R.P. Cowburn, A.O. Adeyeye, and M.E. Welland, Phys. Rev. Lett. 81, 5414 (1998).
22. R.P. Cowburn, D.K. Koltsov, A.O. Adeyeye, and M.E. Welland, Europhys. Lett. 48, 221 (1999).
23. The self-demagnetizing tensor is diagonal for rectangular prisms: (formula presented) A. Aharoni, J. Appl. Phys. 83, 3432 (1998).
24. D.A. Garanin, E.C. Kennedy, D.S.F. Crothers, and W.T. Coffey, Phys. Rev. E 60, 6499 (2000).
25. J. Miltat and A. Thiaville, Science 290, 466 (2000).
26. C.H. Back, R. Allenspach, W. Weber, S.S.P. Parkin, D. Weller, E.L. Garwin, and H.C. Siegmann, Science 285, 864 (1999).