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Computer Simulations of Thermal Switching in Small-Grain Ferromagnets

Published online by Cambridge University Press:  10 February 2011

M. A. Novotny
Affiliation:
Supercomputer Computations Research Institute, Florida State U., Tallahassee, FL 32306-4130, USA; [email protected]; [email protected]; [email protected]
G. Brown
Affiliation:
Supercomputer Computations Research Institute, Florida State U., Tallahassee, FL 32306-4130, USA; [email protected]; [email protected]; [email protected] Center for Materials Research and Technology and Department of Physics, Florida State U., Tallahassee, FL 32306-4350
P. A. Rikvold
Affiliation:
Supercomputer Computations Research Institute, Florida State U., Tallahassee, FL 32306-4130, USA; [email protected]; [email protected]; [email protected] Center for Materials Research and Technology and Department of Physics, Florida State U., Tallahassee, FL 32306-4350
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Abstract

We present Monte Carlo and Langevin micromagnetic calculations to investigate thermal switching of single-domain ferromagnetic particles. For the Monte Carlo study we place particular emphasis on the probability that the magnetization does not switch by time t, Pnot(t). We find that Pnot(t) has different behaviors in different regimes of applied field, temperature, and system size, and we explain this in terms of different reversal mechanisms that dominate in the different regimes. In the micromagnetic study of an array of Ni pillars, we show that the reversal mode is an ‘outside-in’ mode starting at the perimeter of the array of pillars.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

1. Kent, A. D., von Molnár, S., Gider, S., and Awschalom, D. D., J. Appl. Phys. 76, 6656 (1994).10.1063/1.358160Google Scholar
2. Wirth, S., Field, M., Awschalom, D. D., and von Molnár, S., Phys. Rev. B, Rapid Communications, in press (1998).Google Scholar
3. Wernsdorfer, W. et al. , Phys. Rev. Lett. 77, 1873 (1996); Phys. Rev. B 55, 11552 (1997); Phys. Rev. Lett. 78, 1791 (1997).10.1103/PhysRevLett.77.1873Google Scholar
4. Lederman, M., Schultz, S., Ozaki, M., Phys. Rev. Lett. 73, 1986 (1994).10.1103/PhysRevLett.73.1986Google Scholar
5. Mallinson, J. C., The Foundations of Magnetic Recording (Academic, New York, 1993), Second Edition.Google Scholar
6. Rikvold, P. A., Tomita, H., Miyashita, S. and Sides, S. W., Phys. Rev. E 49, 5080 (1994).Google Scholar
7. Richards, H. L. et al. , J. Magn. Magn. Mater. 150, 37 (1995).10.1016/0304-8853(95)00402-5Google Scholar
8. Richards, H. L. et al. , Phys. Rev. B 54, 4113 (1996).10.1103/PhysRevB.54.4113Google Scholar
9. Richards, H. L. et al. , Phys. Rev. B 55, 11521 (1997).10.1103/PhysRevB.55.11521Google Scholar
10. For a review see Rikvold, P. A., Novotny, M. A., Kolesik, M., and Richards, H. L., in Dynamical Properties of Unconventional Magnetic Systems, edited by Skjeltorp, A. T. and Sherrington, D., NATO Science Series E: Applied Sciences, Vol. 349 (Kluwer, Dordrecht, 1998).Google Scholar
11. Novotny, M. A., Phys. Rev. Lett. 74, 1 (1995), Erratum 75, 1424 (1995);10.1103/PhysRevLett.74.1Google Scholar
Kolesik, M., Novotny, M. A., and Rikvold, P. A., Phys. Rev. Lett. 80, 3384 (1998).10.1103/PhysRevLett.80.3384Google Scholar
12. Voter, A. F., Phys. Rev. Lett. 78, 3908 (1997);10.1103/PhysRevLett.78.3908Google Scholar
J. Chem. Phys. 106, 4665 (1997).10.1063/1.473503Google Scholar
13. Aharoni, A., Introduction to the Theory of Ferromagnetism, (Clarendon Press, Oxford, 1996).Google Scholar
14. Brown, W. F., Phys. Rev. 130, 1677 (1963).10.1103/PhysRev.130.1677Google Scholar
15. Binder, K., in Monte Carlo Methods in Statistical Physics, edited by Binder, K., (Springer, Berlin, 1979).10.1007/978-3-642-96483-1Google Scholar
16. Martin, P. A., J. Stat. Phys. 16, 149 (1977).10.1007/BF01418749Google Scholar
17. Boerner, E. D. and Bertram, H. N., IEEE Trans. Magn. 33, 3052 (1997).10.1109/20.617841Google Scholar
18. Garanin, D. A., Phys. Rev. B 55, 3050 (1997).10.1103/PhysRevB.55.3050Google Scholar
19. Brown, G., Novotny, M.A., and Rikvold, P.A., in preparation.Google Scholar
20. Néel, L., Ann. Phys., Paris 3, 137 (1948).10.1051/anphys/194812030137Google Scholar