R. R. Murtazin

Studying the Nucleation and Evolution of Magnetic Inhomogeneities of the Soliton and Breather Type in Magnetic Materials with Local Inhomogeneities of Anisotropy

Numerical methods were used to investigate the dynamics of 180° domain walls in magnets with inhomogeneous parameters of magnetic anisotropy and the conditions for the excitation and evolution of strongly nonlinear waves (solitons and breathers). Three types of magnetic inhomogeneities have been revealed, which appear in the region of the inhomogeneity of anisotropy; these are a damped quiescent breather, a quiescent breather transforming into a soliton, and a soliton. The ranges of the values of the parameters which determine the possibility of existence of each of these inhomogeneities have been determined.

One-dimensional dynamics of domain walls in a three-layer ferromagnetic structure with different parameters of magnetic anisotropy and exchange of the layers

The one-dimensional nonlinear dynamics of a domain wall under the effect of an external dc magnetic field in three-layer ferromagnets with different values of the parameters of magnetic anisotropy and exchange in the layers has been studied theoretically. Equations of motion for the coordinate of the center of a domain wall and for the velocity of its motion after passage from one layer into another has been found using perturbation-theory methods. It is shown that, in the case of small defects, the analytical results agree well with the numerical results. The minimum velocity required for a domain wall to pass from one layer into another has been found numerically as a function of the parameters of the material.

Transformation of SineGordon Solitons in Models with Variable Coefficients and Damping

The dynamics of sine-Gordon solitons in the presence of an external force, damping, and a spatially modulated periodic potential is studied. Numerical methods are used to show the possibility of generating localized nonlinear waves of the soliton and breather types. Their evolution is investigated, and the dependences of the amplitude and the oscillation frequency on the parameters of the system are found.

Simulation of the Nonlinear Dynamics of Magnetic Inhomogeneities in Real Magnets

The dynamics of domain walls (DW) in an infinite ferromagnet containing a flat layer with parameters of magnetic anisotropy and exchange interaction differing from the bulk values was investigated. The dependences of the minimum velocity of DW transmission through the defect region and the translational and pulsation modes of DW fluctuations on the parameters describing the inhomogeneity of magnetic anisotropy and exchange interaction were found.

Excitation of nonlinear solitary flexural waves in a moving domain wall

AbstractNumerical methods have been used to study the dynamics of a 180 °C domain wall described by a modified sine-Gordon equation, in an infinite ferromagnet with a weak ferromagnetism. The dynamics of solitary flexural waves, which appear upon the intersection of a domain wall with a local region of material with magnetic-anisotropy parameters differing from those of the basic volume of the ferromagnet, has been investigated. The case where the width of the domain wall and the size that characterizes the inhomogeneity of the magnetic-anisotropy parameter % MathType!MTEF!2!1!+- % feaagaart1ev2aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXguY9 % gCGievaerbd9wDYLwzYbWexLMBbXgBcf2CPn2qVrwzqf2zLnharyav % P1wzZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqi-u0Je9sqqrpepC % 0xbbL8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yq % aqpepae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabe % qaamaaeaqbaaGcbaGafm4saSKbaGaaaaa!3D15!

Numerical simulation of the generation of magnetic inhomogeneities in ferromagnets with inhomogeneous parameters

\tilde K

Nucleation and evolution of magnetic inhomogeneities of the pulson and 2D soliton type in magnets with local anisotropy inhomogeneities

are of the same order is considered. It is shown that a solitary flexural wave can be considered as one of the “kink-on-kink” solutions of the sine-Gordon equation.

One-dimensional dynamics of domain walls in two-layer ferromagnet structure with different parameters of magnetic anisotropy and exchange

The domain walls dynamics and generation and evolution of magnetic inhomogeneities of soliton type, emerging in a thin flat layer with the parameters of the magnetic anisotropy, which are different from other two thick layers of the five-layer ferromagnetic structure, were investigated.