Abstract
The magnetization curve and magnetization correlation function are calculated for a ferromagnetic chain of single-domain nanoparticles with a randomly oriented anisotropy axis for different ratios between the exchange correlation and anisotropy energies. It is shown that the coercive force decreases as the exchange correlations increase. For strong exchange correlations, the magnetization curve is described by the following three successive magnetization processes as the applied field is increased: (i) nonuniform rotation of the magnetization of stochastic domains, (ii) collapse of the magnetic solitons, and (iii) nonuniform rotation of exchange-correlated magnetization vectors of the nanoparticles. For high fields, the calculated correlation function of the transverse magnetization components coincides with that predicted from linear theory. At low and zero fields, the main parameters of the correlation function (the variance and correlation radius) tend to certain finite values rather than diverge (as is the case in linear theory). The irreversible variation in the magnetization at low fields (the hysteresis loop) and the hysteresis of the main parameters of the correlation function are calculated.
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References
V. A. Ignatchenko and R. S. Iskhakov, Zh. Éksp. Teor. Fiz. 72, 1005 (1977) [Sov. Phys. JETP 45, 526 (1977)].
R. Alben, J. J. Becker, and M. C. Chi, J. Appl. Phys. 49, 1653 (1978).
G. Herzer, IEEE Trans. Magn. 26, 1397 (1990).
Y. Imry and S.-K. Ma, Phys. Rev. Lett. 35, 1399 (1975).
J. M. Ziman, Models of Disorder: The Theoretical Physics of Homogeneously Disordered Systems (Cambridge Univ. Press, London, 1979; Mir, Moscow, 1982).
J. Weissmuller, A. Michels, J. G. Barker, A. Wiedenmann, U. Erb, and R. D. Shull, Phys. Rev. B 63, 214414 (2001).
A. Michels, R. N. Viswanath, J. G. Barker, R. Birringer, and J. Weissmuller, Phys. Rev. Lett. 91, 267204 (2003).
V. A. Ignatchenko, R. S. Iskhakov, and G. V. Popov, Zh. Éksp. Teor. Fiz. 82, 1518 (1982) [Sov. Phys. JETP 55, 878 (1982)].
R. S. Iskhakov, S. V. Komogortsev, Zh. M. Moroz, and E. E. Shalygina, Pis’ma Zh. Éksp. Teor. Fiz. 72, 872 (2000) [JETP Lett. 72, 603 (2000)].
R. S. Iskhakov, V. A. Ignatchenko, S. V. Komogortsev, and A. D. Balaev, Pis’ma Zh. Éksp. Teor. Fiz. 78, 1142 (2003) [JETP Lett. 78, 646 (2003)].
H. Kronmuller, R. Fischer, M. Seeger, and A. Zern, J. Phys. D: Appl. Phys. 29, 2274 (1996).
R. Fischer and H. Kronmuller, J. Magn. Magn. Mater. 184, 166 (1998).
J. Fidler and T. Schrefl, J. Magn. Magn. Mater. 203, 28 (1999).
W. M. Saslow and N. C. Koon, Phys. Rev. B 49, 3386 (1994).
O. Nedelko, P. Dikukh, and A. Slawska-Waniewska, J. Magn. Magn. Mater. 254–255, 281 (2003).
I. R. McFadyen and I. A. Beardsley, J. Appl. Phys. 67, 5540 (1990); I. A. Beardsley and J. S. Zhu, J. Appl. Phys. 67, 5352 (1990).
R. Dickmann and E. M. Chudnovsky, Phys. Rev. B 44, 4397 (1991).
A. A. Ivanov, V. A. Orlov, and G. O. Patrushev, Fiz. Met. Metalloved. 84(2), 47 (1997) [Phys. Met. Metallogr. 84, 125 (1997)].
A. A. Ivanov and G. O. Patrushev, Fiz. Met. Metalloved. 86(4), 1 (1998) [Phys. Met. Metallogr. 86, 331 (1998)].
A. A. Ivanov, V. A. Orlov, and G. O. Patrushev, Fiz. Tverd. Tela (St. Petersburg) 41, 1432 (1999) [Phys. Solid State 41, 1311 (1999)].
B. Dieny and B. Barbara, Phys. Rev. B 41, 11549 (1990).
D. R. Denholm and T. J. Sluckin, Phys. Rev. B 48, 901 (1993).
H. Zeng, R. Skomski, L. Menon, Y. Liu, S. Bandyopadhyay, and D. J. Sellmyer, Phys. Rev. B 65, 134426 (2002).
R. S. Iskhakov, S. V. Komogortsev, A. D. Balaev, A. V. Okotrub, A. G. Kudashov, V. L. Kuznetsov, and Yu. V. Butenko, Pis’ma Zh. Éksp. Teor. Fiz. 78, 271 (2003) [JETP Lett. 78, 236 (2003)].
E. C. Stoner and E. P. Wohlfarth, Philos. Trans. R. Soc. London, Ser. A 240, 599 (1948).
R. S. Iskhakov, S. V. Komogortsev, A. D. Balaev, and L. A. Chekanova, Pis’ma Zh. Éksp. Teor. Fiz. 72, 440 (2000) [JETP Lett. 72, 304 (2000)].
R. Skomski, J. Phys.: Condens. Matter 15, R841 (2003).
V. A. Ignatchenko, Zh. Éksp. Teor. Fiz. 54, 303 (1968) [Sov. Phys. JETP 27, 162 (1968)].
V. A. Ignatchenko and R. S. Iskhakov, Fiz. Met. Metalloved., No. 6, 75 (1992).
A. V. Luk’yanenko and S. V. Komogortsev, in Proceedings of the II Baikal International Conference on Magnetic Materials (Irkutsk, 2003), p. 72.
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Translated from Fizika Tverdogo Tela, Vol. 47, No. 3, 2005, pp. 480–486.
Original Russian Text Copyright © 2005 by Komogortsev, Iskhakov.
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Komogortsev, S.V., Iskhakov, R.S. Magnetization curve and magnetic correlations in a nanochain of ferromagnetic grains with random anisotropy. Phys. Solid State 47, 495–501 (2005). https://doi.org/10.1134/1.1884711
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DOI: https://doi.org/10.1134/1.1884711