Dynamics of localized magnetic inhomogeneities in the five-layer ferromagnetic structure

E.G. Ekomasov1, A.M. Gumerov1, R.V. Kudryavtsev1
1Bashkir State University, Z. Validi St. 32, Ufa
Abstract
The paper considers the five-layer ferromagnetic structure, consisting of three identical wide layers separated by two thin layers with of the same the changed values of the anisotropy parameter. Anisotropy parameters are considered to be functions of the coordinate, directed perpendicular to the interface between the layers, i.e. we believe that the system has two magnetic "defects." Has been studied the case of magnetic point defects described by a Dirac delta function with the parameters of the magnetic anisotropy different from the values of the magnetic anisotropy parameter in the rest of the magnet. With an approximate collective coordinate approach used previously to analyze the vibrations localized nonlinear magnetization waves at a single point defect theoretically studied the collective effect of two identical magnetic defects on the dynamics of coupled nonlinear magnetization waves. Has been studied the structure and dynamics of localized magnetic inhomogeneity of type four-kink multisoliton. For small amplitudes shown that oscillations of the magnetic multisoliton can be described as a system of two harmonic oscillators with elastic coupling type with the same natural frequency. In this case, the coupling coefficient can be varied, for example, by changing the distance between the defects. With increasing distance between defects, the coupling coefficient is reduced to zero, and the system is transformed into a system of differential equations for the uncoupled harmonic oscillators. In the case of reducing the distance between the defects is observed increase "stiffness" by effective communication between the oscillators.
Received: 15 April 2016   Revised: 12 May 2016   Accepted: 13 May 2016
Views: 47   Downloads: 20
References
1.
A. Hubert, R. Schafer. Magnetic domains. Springer-Verlag, Hedelberg, Berlin. (1998) 696 p.
2.
A.B. Borisov, V.V. Kiselev. Nonlinear waves, solitons and localized structures in magnetic materials. T.1. Quasi-one-dimensional magnetic solitons. UB RAS, Ekaterinburg. (2009) 512 p. (in Russian) [А.Б. Борисов, В.В. Киселёв. Нелинейные волны, солитоны и локализованные структуры в магнетиках. Т.1. Квазиодномерные магнитные солитоны. УрО РАН, Екатеринбург. (2009) 512 с.
3.
E. Della Torre, C.M. Perlov. J. Appl. Phys. 69, 4596 (1991).
4.
V.N. Nazarov, R.R. Shafeev, M.A. Shamsutdinov, I.Yu Lomakina. Phys. Solid State. 54, 298 (2012). (in Russian) [В.Н. Назаров, Р.Р. Шафеев, М.А. Шамсутдинов, И.Ю. Ломакина. ФТТ. 54(2), 282 (2012).]
5.
V.V. Kiselev, A.A. Rascovalov. Chaos, Solitons & Fractals. 45, 1551 (2012).
6.
V.V. Kruglyak, A.N. Kuchko, V.I. Finokhin. Phys. Solid State. 46, 867 (2004). (in Russian) [В.В. Кругляк, А.Н. Кучко, В.И. Финохин. ФТТ. 46(5), 842 (2004).]
7.
E. G. Ekomasov, A. M. Gumerov, R. R. Murtazin, R. V. Kudryavtsev, A. E. Ekomasov, N. N. Abakumova. Solid state phenomena. 233-234, 51-54 (2015).
8.
E.G. Ekomasov, R.R. Murtazin, V.N. Nazarov. Journal of Magnetism and Magnetic Materials. 385, 217 (2015).
9.
V.A. Ignatchenko, Yu.I. Mankov, A.A. Maradudin. Phys. Rev. B. 62(3), 2181 (2000).
10.
J. Cuevas-Maraver, P. G. Kevrekidis, F. Williams (Eds.). The Sine-Gordon Model and Its Applications: From Pendula and Josephson Junctions to Gravity and High-energy Physics, volume 10. Springer. (2014) 263 p.
11.
E.G. Ekomasov, R.R. Murtazin, O.B. Bogomazova, A.M. Gumerov. JMMM. 339, 133 (2013).
12.
E. G. Ekomasov, A. M. Gumerov. Letters on materials. 4, 237 (2014). (in Russian) [Е.Г. Екомасов, А.М. Гумеров. Письма о материалах. 4(4), 237 (2014).]