Quantum limit of magnetic recording density

Applied Physics Letters

Volumn 79, Issue 10, 2001, Pages 1501-1503

  Held, G A ^a   Grinstein, G ^a  

^a IBM T J WATSON RESEARCH CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0345821945     PISSN: 00036951     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.1396317     Document Type: Article

References (23)

1. D. Weller and A. Moser, IEEE Trans. Magn. 35, 4423 (1999).
2. H. J. Richter and R. Y. Ranjan, J. Magn. Magn. Mater. 193, 213 (1999).
3. H. N. Bertram, H. Zhou, and R. Gustafson, IEEE Trans. Magn. 34, 1845 (1998).
4. C. P. Bean and J. D. Livingston, J. Appl. Phys. 30, 120S (1959).
5. D. Weller, A. Moser, L. Folks, M. E. Best, W. Lee, M. F. Toney, M. Schwickert, J.-U. Thiele, and M. F. Doerner, IEEE Trans. Magn. 36, 10 (2000).
6. Temperature dependence of the anisotropy (K) results in only modest changes in the write field and energy barrier.
7. E. M. Chudnovsky and J. Tejada, Macroscopic Quantum Tunneling of the Magnetic Moment (Cambridge University Press, Cambridge, 1998); see also, e.g., E. M. Chudnovsky and L. Gunther, Phys. Rev. Lett. 60, 661 (1988); M.-C. Miguel and E. M. Chudnovsky, Phys. Rev. B 54, 388 (1996).
8. E. M. Chudnovsky and J. Tejada, Macroscopic Quantum Tunneling of the Magnetic Moment (Cambridge University Press, Cambridge, 1998); see also, e.g., E. M. Chudnovsky and L. Gunther, Phys. Rev. Lett. 60, 661 (1988); M.-C. Miguel and E. M. Chudnovsky, Phys. Rev. B 54, 388 (1996).
9. E. M. Chudnovsky and J. Tejada, Macroscopic Quantum Tunneling of the Magnetic Moment (Cambridge University Press, Cambridge, 1998); see also, e.g., E. M. Chudnovsky and L. Gunther, Phys. Rev. Lett. 60, 661 (1988); M.-C. Miguel and E. M. Chudnovsky, Phys. Rev. B 54, 388 (1996).
10. J. Li, M. Mirzamaani, X. Bian, M. Doerner, S. Duan, K. Tang, M. Toney, T. Arnoldussen, and M. Madison, J. Appl. Phys. 85, 4286 (1999).
11. S. Sun, C. B. Murray, D. Weller, L. Folks, and A. Moser, Science 287, 1989 (2000).
12. E. C. Stoner and E. P. Wohlfarth, Trans. R. Soc. A 240, 599 (1948).
13. L. Néel, Ann. Geophys. (C.N.R.S.) 5, 99 (1949); W. F. Brown, Phys. Rev. 130, 1677 (1963).
14. L. Néel, Ann. Geophys. (C.N.R.S.) 5, 99 (1949); W. F. Brown, Phys. Rev. 130, 1677 (1963).
15. J. L. van Hemmen and A. Sütö, Physica B 141, 37 (1986); see also, M. Enz and R. Schilling, J. Phys. C 19, 1765 (1986).
16. J. L. van Hemmen and A. Sütö, Physica B 141, 37 (1986); see also, M. Enz and R. Schilling, J. Phys. C 19, 1765 (1986).
17. d approaches the critical value which makes the energy barrier vanish.
18. Media based on this alloy have been distributed within the National Storage Industry Consortium (NSIC) and characterized at a number of laboratories (Ref. 1).
19. This estimate of volume assumes perfectly uniform grain sizes. However, it is easy to see that the relative error in our estimate cannot exceed the relative width of the distribution. Thus a collection of nanoparticles with a 10% spread in volume, e.g., will satisfy Eq. (7) for an average particle volume that is within 10% of our estimate.
20. rδ from Ref. 8, we estimate δ≈D.
21. average≈2D/3.
22. H. N. Bertram and M. Williams, IEEE Trans. Magn. 36, 4 (2000).
23. Temperature assisted writing schemes could potentially alleviate this problem: H. Katayama, S. Sawamura, Y. Ogimoto, K. Kojima, and K. Ohta, J. Magn. Soc. Jpn. 23, 233 (1999).