Possible schemes for creating superlattices for channeled waves in magnetically ordered media by modulating their parameters by extraneous waves are discussed.

This work proposes a new fractal model of a complex near-surface domain structure that assembles itself in highly anisotropic uniaxial single crystals, and which is based on a previously unknown modification of the Sierpinski carpet. The simulation algorithm is described and an example of its application is given.

The features of propagation of coupled hybrid transverse elastic waves in a nonuniform dense micropolar medium with spatial dispersion are studied. It is shown that in the region of the medium corresponding to the intersection point of unperturbed dispersion curves of elastic waves of different types, efficient transformation of a shear wave into a rotational wave or vice versa may occur.

Для цифровой магнитной записи кодированной информации с продольным намагничиванием ленты изучена связь между доменной структурой носителя и магнито-оптическим изображением его полей рассеяния, полученным с помощью магнитной пленки с перпендикулярной анизотропией и большим фарадеевским вращением. Для двухчастотного двоичного кода без возвращения к нулю разработан алгоритм, позволяющий на основе анализа изображения полей рассеяния однозначно расшифровать записанную на ленте информацию. DOI: 10.21883/PJTF.2017.09.44575.16321

For digital magnetic recording of encoded information with longitudinal magnetization of the tape, the connection between the domain structure of a storage medium and magneto-optical image of its stray fields obtained using a magnetic film with a perpendicular anisotropy and a large Faraday rotation has been studied. For two-frequency binary code without returning to zero, an algorithm is developed, that allows uniquely decoding of the information recorded on the tape based on analysis of an image of stray fields.

The form of phase diagrams has been determined for epitaxial magnetic films of the composition Y3–x–y Bi x Pr y Fe5O12 on the plane (H ‖ H ⊥), where H ‖ and H ⊥ are the external magnetic field components parallel and orthogonal, respectively, to the direction of the normal n to the surface of the film. The specific features have been revealed in the magnetization reversal of the objects under investigation, which are associated with their structural stratification.

The properties of epitaxial magnetic (LuBi)3(FeGa)5O12 iron garnet films grown on (210) substrates, which exhibit the magnetoelectric effect, are experimentally studied. The induced anisotropy and the behavior of the domain structure in the films are investigated in uniform and nonuniform external fields. The existing hypotheses about the nature of the magnetoelectric coupling in such films are critically analyzed.

The distribution of the magnetization vector on the free surface and end (cleaved facet) of thick epitaxial yttrium iron garnet films has been studied by the scanning magnetic-force microscopy method. Volume fractal-like branching of the domain structure has been found at the interface of the film and the free space with the refinement of the formed partial branches of the stripe (labyrinth) domains. Triangular closing domains have been observed at the interface between the film and the substrate. Direct experimental proof of the existence of the static horizontal Bloch lines within the stripe domain walls has been obtained.

The mechanism underlying the strong magnetoelectric effect in epitaxial films of magnetic garnet is proposed. This mechanism is not related to the existence of the electrically charged domain walls. It results from the effect of a nonuniform electric field on the induced magnetic anisotropy and depends on the crystallographic orientation of the films.

The influence of monoperiodic and biperiodic bias fields on the nucleation of domain structures in quasi-uniaxial magnetic films near the Curie point has been studied experimentally. The main types of observed nonuniform magnetic moment distributions have been established and chains of a devil's staircase phase transitions are shown to be realized when the films are slowly cooled.

Fourier images corresponding to diffraction patterns in the Fraunhofer zone were obtained for a set of fractal objects by means of computer simulation with the use of net functions. The fractal dimensions of the objects being investigated were determined on the basis of the intensity distribution in the diffraction patterns.

The behavior of biperiodic stripe domain structures in quasi-uniaxial magnetic films with a near-critical thickness is studied by scanning magnetic force microscopy and magnetooptical diffraction. In these films, antiphase and hybrid biperiodic domain structures are found to be absent, and the phase transitions between monoperiodic and in-phase biperiodic domain structures are shown to proceed through two-dimensional domain arrays that are amorphized in the arrangement of near-surface distortions in the domain-wall profile.

Magnetic analogues of the Kapitza pendulum have been implemented in systems formed by one or two compass arrows in an oscillating magnetic field. The complete state diagrams for the systems studied have been determined. It is experimentally confirmed that two dynamically stabilized equilibrium states coexist in the system of two magnetic arrows.

Results of theoretical and experimental investigation of magnetooptic light diffraction by biperiodic stripe domain structures are presented. Such structures exist in ferrite films made from uniaxial magnetic garnets with small positive anisotropy constants. Effects of an external magnetic field and of the film thickness on the symmetry of observed diffraction patterns and on the distribution of the light intensity in different diffraction maxima are studied. Changes in the symmetry of Fourier transforms are shown to occur during phase transitions between different types of biperiodic stripe domain structures. Theoretical calculations of the light intensity of diffracted radiation are shown to agree well with experimental data.

A fractal-like structure of the domain boundaries was revealed in “overcritical” uniaxial Permalloy magnetic films. The fractal dimension of domain boundaries at the film surfaces was determined as a function of the film thickness. It is shown that the phase transition between the two possible types of fractal-like structures is accompanied by a jump in fractal dimension.

Behavior of the magnetic susceptibility of quasi-uniaxial ferromagnetic films in the vicinity of the Curie point was studied with allowance for a periodic spatial inhomogeneity in the distribution of the magnetization vector for an arbitrary frequency ω of an external magnetic field. In the presence of a constant bias magnetic field H 0 , the temperature dependence of the real and imaginary parts of the magnetic susceptibility exhibits, in the general case, both frequency-independent extrema and numerous additional extrema having shapes and positions dependent on frequency.