[Image] Vol Page/Article: ------------------------------------------------------------------------ Article Collection: View Collection Help (Click on the [COLLECT ARTICLE] to add an article.) ------------------------------------------------------------------------ Article Collection functions work best when viewed with a JavaScript-capable and -enabled browser (see the online help for more information). [ Previous / Next Abstract | Issue Table of Contents | Bottom of Page ] Physical Review B (Condensed Matter and Materials Physics) -- March 1, 1999 -- Volume 59, Issue 10, pp. 6956-6965 [Image] Full Text: [ PDF (1141 kB) GZipped PS Order Document ] ------------------------------------------------------------------------ Magnetic irreversibility and relaxation in assembly of ferromagnetic nanoparticles R. Prozorov Loomis Laboratory of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 Y. Yeshurun Institute of Superconductivity, Department of Physics, Bar-Ilan University, 52900 Ramat-Gan, Israel T. Prozorov and A. Gedanken Department of Chemistry, Bar-Ilan University, 52900 Ramat-Gan, Israel (Received 21 July 1998) Measurements of the magnetic irreversibility line and time-logarithmic decay of the magnetization are described for three Fe2O3 samples composed of regular amorphous, acicular amorphous, and crystalline nanoparticles. The relaxation rate is the largest and the irreversibility temperature is the lowest for the regular amorphous nanoparticles. The crystalline material exhibits the lowest relaxation rate and the largest irreversibility temperature. We develop a phenomenological model to explain the details of the experimental results. The main new aspect of the model is the dependence of the barrier for magnetic relaxation on the instantaneous magnetization and therefore on time. The time-dependent barrier yields a natural explanation for the time-logarithmic decay of the magnetization. Interactions between particles as well as shape and crystalline magnetic anisotropies define an energy scale that controls the magnetic irreversibility. Introducing this energy scale yields a self-consistent explanation of the experimental data. ©1999 The American Physical Society URL: http://link.aps.org/abstract/PRB/v59/p6956 PACS: 75.50.Tt, 75.60.Lr, 75.30.Gw Additional Information ------------------------------------------------------------------------ [Image] Full Text: [ PDF (1141 kB) GZipped PS Order Document ] ------------------------------------------------------------------------ References Citation links [e.g., Phys. Rev. D 40, 2172 (1989)] go to online journal abstracts. Other links (see Reference Information) are available with your current login. Navigation of links may be more efficient using a second browser window. 1. J. Frenkel and J. Dorfman, Nature (London) 126, 274 (1930). 2. L. D. Landau and E. M. Lifschitz, Electrodynamics of Continuous Media (Pergamon, Oxford, England, 1984). 3. C. G. Montgomery, Phys. Rev. 38, 1782 (1931). 4. W. C. Elmore, Phys. Rev. 54, 1092 (1938). 5. C. P. Bean and J. D. Livingston, J. Appl. Phys. 30, 120S (1959). 6. C. P. Bean and I. S. Jacobs, J. Appl. Phys. 27, 1448 (1956); J. S. Jacobs and C. P. Bean, in Magnetism, edited by J. T. Rado and H. Suhl (Academic, New York, 1963), p. 271. 7. W. Luo, S. R. Nagel, T. F. Rosenbaum, and R. E. Rosensweig, Phys. Rev. Lett. 67, 2721 (1991). 8. M. Hanson, C. Johansson, M. S. Pedersen, and S. Morup, J. Phys.: Condens. Matter 7, 9269 (1995). [INSPEC] 9. J. A. Mydosh, J. Magn. Magn. Mater. 157/158, 606 (1996). [INSPEC] 10. M. G. del Muro, X. Batlle, A. Labarta, J. M. Gonzalez, and M. I. Montero, J. Appl. Phys. 81, 7427 (1997). 11. K. S. Suslick, S.-B. Choe, A. A. Cichowlas, and M. W. Grinstaff, Nature (London) 353, 414 (1991). [INSPEC] 12. X. Cao, Y. Koltypin, R. Prozorov, G. Kataby, I. Felner, and A. Gedanken, J. Mater. Res. 12, 402 (1997). [SPIN] 13. T. Prozorov, R. Prozorov, Y. Koltypin, I. Felner, and A. Gedanken, J. Phys. Chem. B 102, 10 165 (1998). 14. P. W. Anderson, Phys. Rev. Lett. 9, 309 (1962). 15. M. R. Beasley, R. Labush, and W. W. Webb, Phys. Rev. 181, 682 (1969). [INSPEC] 16. Y. Yeshurun, A. P. Malozemoff, and A. Shaulov, Rev. Mod. Phys. 68, 911 (1996). 17. S. Morup and E. Tronc, Phys. Rev. Lett. 72, 3278 (1994). 18. W. T. Coffey and D. S. F. Crothers, Phys. Rev. E 54, 4768 (1996). 19. J. E. Wegrowe, J. P. Meier, B. Doudin, J. P. Ansermet, W. Wernsdorfer, B. Barbara, W. T. Coffey, Y. P. Kalmykov, and J. L. Dejardin, Europhys. Lett. 38, 329 (1997). [INSPEC] 20. C. Sanchez, J. M. Gonzalez-Miranda, and J. Tejada, J. Magn. Magn. Mater. 140-144, 365 (1995). [INSPEC] 21. A. Aharoni, Introduction to the Theory of Ferromagnetism (Clarendon, Oxford, 1996). 22. S. Morup, M. B. Madsen, J. Franck, J. Villadsen, and C. J. W. Koch, J. Magn. Magn. Mater. 40, 163 (1983). [INSPEC] 23. S. Morup, Europhys. Lett. 28, 671 (1994). [INSPEC] 24. S. Bocquet, R. J. Pollard, and J. D. Cashion, Phys. Rev. B 46, 11 657 (1992). 25. M. El-Hilo, K. O'Grady, and R. W. Chantrell, J. Magn. Magn. Mater. 114, 307 (1992). [INSPEC] 26. T. Bitoh, K. Ohba, M. Takamatsu, T. Shirane, and S. Chikazawa, J. Magn. Magn. Mater. 154, 59 (1996) (ScienceDirect). [INSPEC] 27. W. T. Coffey and Y. P. Kalmykov, J. Magn. Magn. Mater. 164, 133 (1996) (ScienceDirect). [INSPEC] 28. L. Balcells, O. Iglensias, and A. Labarta, Phys. Rev. B 55, 8940 (1997). 29. M. G. del Muro, X. Batlle, A. Labarta, J. M. Gonzalez, and M. I. Montero, J. Appl. Phys. 81, 3812 (1997). 30. Y. L. Raikher and V. I. Stepanov, Phys. Rev. B 55, 15 005 (1997). 31. S. U. Jen, C. Y. Lee, Y. D. Yao, and K. C. Lee, J. Magn. Magn. Mater. 96, 82 (1991). [INSPEC] 32. M. W. Grinstaff, M. B. Salamon, and K. S. Suslick, Phys. Rev. B 48, 269 (1993). 33. D. K. Lottis, R. M. White, and E. Dan Dahlberg, Phys. Rev. Lett. 67, 362 (1991). 34. R. D. Kirby, J. X. Shen, R. J. Hardy, and D. J. Sellmyer, Phys. Rev. B 49, 10 810 (1994); A. Liberatos, J. Earl, and R. W. Chantrell, 53, 5493 (1996). 35. J. P. Bouchard and P. G. Zerah, Phys. Rev. B 47, 9095 (1993). 36. M. A. Zaluska-Kotur and M. Cieplak, Europhys. Lett. 23, 85 (1993). [INSPEC] 37. L. Néel, Ann. Geophys. (C.N.R.S.) 5, 99 (1949). 38. S. Morup and G. Christiansen, J. Appl. Phys. 73, 6955 (1993). 39. S. Linderoth, L. Balcells, A. Labarta, J. Tejada, P. V. Hendriksen, and S. A. Sethi, J. Magn. Magn. Mater. 124, 269 (1993). [INSPEC] 40. E. Viitala, J. Merikoski, M. Manninen, and J. Timonen, Phys. Rev. B 55, 11 541 (1997). [Image] The American Physical Society is a member of CrossRef. ------------------------------------------------------------------------ [Image] Full Text: [ PDF (1141 kB) GZipped PS Order Document ] ------------------------------------------------------------------------ Citing Articles This list contains links to other online articles that cite the article currently being viewed. 1. Magnetic properties of nanoparticles in the Bethe-Peierls approximation Luis G. C. Rego et al., Phys. Rev. B 64, 144424 (2001) 2. Granular Cu-Co alloys as interacting superparamagnets Paolo Allia et al., Phys. Rev. B 64, 144420 (2001) 3. Magnetic relaxation in bulk and film manganite compounds M. Sirena et al., Phys. Rev. B 64, 104409 (2001) 4. Ising Ferromagnetism and Domain Morphology in the Fractional Quantum Hall Regime J. H. Smet et al., Phys. Rev. Lett. 86, 2412 (2001) ------------------------------------------------------------------------ [Image] Full Text: [ PDF (1141 kB) GZipped PS Order Document ] [ Previous / Next Abstract | Issue Table of Contents | Top of Page ] ------------------------------------------------------------------------ Article Collection: View Collection Help (Click on the [COLLECT ARTICLE] to add an article.) ------------------------------------------------------------------------ [ Homepage | Browse Available Volumes | Search | Subscriptions | Contact Information | Online Help | Exit ]