A perforated plane ferromagnetic film with the inhomogeneous magnetoelectric interaction is theoretically studied. It is shown that an applied electric field can change the topology of the magnetic structure in such a film. Moreover, it is demonstrated that the distribution of the electric potential ensuring the occurrence of an arbitrary predetermined topology of the magnetic structure can be found. Explicit expressions determining the topology of the magnetic structure at the potential distribution are presented for the general and some particular cases.

The paper theoretically studies the influence of inhomogeneous magnetoelectric interaction on systems of vortex-like objects formed in a film of a planar ferromagnet. It is shown that each of these objects interacts with an electric field as a point charge of a certain magnitude (in particular, the object 'feels' the field only in its center). It is revealed that fields of sufficiently high strength can promote the spontaneous generation of a vortex-antivortex pair due to the amplification of fluctuations in the magnetization distribution in the film.

In this paper, a circular ring monopole antenna, along with its MIMO configuration sub-7 GHz and mm-wave 5G applications is presented. The single element frequencies in the sub-6 GHz and mm-wave regions, including a triple-band 23.3-33.5 GHz, and a super-wide band starting from 37.5 GHz. A two-element derived from the single element, has been developed to operate in both frequency - 10 dB criterion with a bandwidth of 4.8 GHz ( 3.2 to 7.3 GHz) in the sub-6 spectrum. Additionally, the antenna exhibits a super-wide band in the mm 30.4 GHz. The design covers key bands such as n78, LTE band 46, n96, 39 GHz

The paper theoretically studies the effect of a non-uniform electric field on thin ferromagnetic films with a planar distribution of magnetization, which are of interest due to certain possibilities for the formation of vortex-like structures in them and the influence of an electric field is one of the most effective approaches to controlling structures of this type. It is proven that in this case the presence of inhomogeneous magnetoelectric interaction has virtually no effect on the magnetic structure of the sample far from its boundaries, but leads to the appearance of edge effects consisting in the formation of solitary magnetic inhomogeneities at the film boundary. In this case, the structure and properties of such inhomogeneities are completely determined by the values of the electric field potential at the sample boundary. Both for the general case and for a number of specific configurations of the external field, the distribution of magnetization in the region of inhomogeneity is found, and its energy is calculated.

The paper investigates the behavior of 0 degree domain boundaries arising in uniaxial magnetic films with flexomagnetoelectric effect in a magnetic field. It is shown that at certain orientations of the magnetic field, it is possible to significantly enhance (or weaken) the degree of manifestation of the flexomagnetoelectric effect in the studied films. In addition, by varying the magnitude and directions of the magnetic field, it is possible to significantly lower (up to zero) the value of the critical electric field of the origin of this inhomogeneity. It is also established that a 0 degree domain boundary of non-Anelian type, in which induced bound charges do not create a resultant field (field shielding), when a magnetic field directed perpendicular to the plane of rotation of magnetic moments is applied, a flexomagnetoelectric effect occurs, which increases with increasing magnitude of the magnetic field.

The paper examines ferromagnetic films with strong uniaxial anisotropy of the “easy plane” type, in which vortex-like inhomogeneities can arise in the presence of artificially created perforations. A universal approach has been developed that makes it possible to reduce the problem of calculating demagnetizing fields in a film of arbitrary thickness to the simplest case, when the film thickness is large. It has been shown that the influence of demagnetizing fields causes the magnetization vector to necessarily move out of the sample plane, and the spatial distribution of magnetization corresponding to this effect has been studied. It has been revealed that the contribution of demagnetizing fields to the total energy of the magnet changes slightly during the transition from a homogeneous structure to an inhomogeneous one.

The study examines the behavior of vortex-like magnetic inhomogeneities that arise in a ferromagnetic disk with spatially modulated uniaxial anisotropy under magnetic fields of varying orientations. The research identifies the characteristic remagnetization stages of the vortex-like inhomogeneities formed in the region of the defect. Critical fields of their rearrangement are found and an explanation is given for the difference in the behavior of these inhomogeneities in perpendicular and planar magnetic fields. The effect of the helicity of the magnetic skyrmion localized at the defect on its remagnetization process in the planar field is revealed.

In this paper, permalloy films containing artificially created nanoscale perforations are studied, and it is theoretically substantiated that in the region of a pair of closely spaced perforations, the formation of topologically protected vortex-like inhomogeneities is possible. Quantitative estimates of the conditions for the existence of inhomogeneities of this type are obtained, and the causes and possible scenarios for their destruction are studied in cases where these conditions are violated.

The work examines ferromagnetic films with strong uniaxial anisotropy of the "easy plane" type and substantiates that paired nano-scaled perforations in such films can be used as memory cells for recording and storing data in the ternary number system. The problem of reading the state of cells of this type has been studied, and an approach to solving it has been proposed, which consists in measuring the response of the system to a picosecond pulse of an external magnetic field. The parameters of the system at which the magnitude of this response is greatest were obtained, and estimates of this value were made using both analytical and numerical methods. -- V rabote issleduyutsya ferromagnitnyje plenki s silnoj odnoosnoj anizotropiej tipa "legkaya ploskost" i obosnovyvaetsya, chto parnyje nanorazmernyje perforacii v takih plenkah mogut byt ispolzovany v kachestve yacheek pamyati dlya zapisi i hraneniya dannyh v troichnoj sisteme ischisleniya. Izuchena problema schityvaniya sostoyaniya yacheek takogo tipa, a takzhe predlozhen podhod k ee resheniyu, zaklyuchayushhijsya v izmerenii otklika sistemy na pikosekundnyj impuls vneshnego magnitnogo polya. Polucheny parametry sistemy, pri kotoryh velichina dannogo otklika okazyvaetsya naibolshej, a takzhe provedeny ocenki etoj velichiny kak analiticheskimi, tak i chislennymi metodami.

In this study, the features of the manifestation of the flexomagnetoelectric effect in a (111)-oriented ferrite garnet film were investigated. It has been shown that, in such magnets, two types of domain walls with magnetization in domains with M 0 ∣ ∣ 111 are possible: a Bloch-type domain wall and a wall with a quasi-Bloch structure. The evolution of each type of domain wall in an increasing electric field with ε ∣ ∣ 111 is revealed, and the characteristic stages of transformation of their structures were determined. Critical fields for their rearrangement and the corresponding values of differential and integral polarizations were found. It has been established that the presence of cubic anisotropy in a (111)-oriented film weakens the degree of manifestation of the flexomagnetoelectric effect in it.

Stability conditions are studied for vortex-like inhomogeneities in perforated ferromagnetic films with strong easy plane uniaxial anisotropy. It is shown that nontrivial magnetic structures characterized by the absence of out of plane magnetization can be observed at absolute values of the anisotropy constant exceeding a certain threshold value. Possible (analytical, numerical, and empirical) methods for calculating this threshold value are developed. Universal estimates of the minimum permissible value of the anisotropy constant are obtained in a number of important cases. Feasible scenarios for the loss of stability of the magnetic structure under the variation of the material parameters of the film are analyzed.

The ferromagnetic film in the electric film of a charged filament is studied theoretically. It has been shown that solitary magnetic inhomogeneities can be formed in this film in the presence of the inhomogeneous magnetoelectric interaction; their structure and nucleation conditions are determined by the sign of interacting charges. In particular, it has been established that the minimum magnitude of the linear charge density for the formation of an inhomogeneity in a positively charged filament is several times different from that for a negatively charged filament.

In this work, we theoretically study the effect of inhomogeneous magnetoelectric interaction on the distribution of magnetization in insulating ferromagnetic films with strong easy-plane anisotropy. It is shown that, depending on the magnitude of the applied electric field, structures of various topologies can form in such films. It has been established that the optimal control of the magnetic structure can be achieved by the field of a charged filament. For this case, all stable and metastable states of the system are studied in detail depending on the field strength and material parameters of the film.

The effect of a magnetic field on the behavior of 180-degree domain walls in a uniaxial ferromagnetic film with an inhomogeneous magnetoelectric interaction has been studied. It has been shown that, depending on the magnitude and direction of the field, it is possible to enhance or weaken the flexomagnetoelectric effect in the sample. In addition, it was found that in the reverse field the switching of the interaction between the electric field source and the domain wall from attraction to repulsion is possible.

The influence of the parameters of the control pulse of a magnetic field with the shape of a rectangular trapezoid on the dynamics of domain walls in ferrite garnets and orthoferrites is studied. The calculation results are compared with experimental data obtained by the high-speed photography method. It is shown that the front edge of the control pulse with duration of less than 80 ns has a slight effect on the dynamics of the domain wall in materials in which the velocity of domain wall motion does not exceed several hundred meters per second. If the domain wall velocity is several kilometers per second, then a front edge with a duration of 50 ns leads to long acceleration of the domain wall to the maximum velocity and reduces the time required for the wall to move with this velocity, thereby limiting the possibility of additional control over the wall dynamics. It is shown that an excessively long front edge of the pulse can lead to a decrease in the maximum velocity of the domain wall and its mobility in the experimental measurements. An excessively short control pulse with a fixed amplitude leads to a decrease in the maximum displacement of the domain wall and, consequently, to a decrease in the time of motion with a constant velocity that corresponds to a given amplitude of the control pulse.

The paper investigates the processes of the magnetization reversal of perforated ferromagnetic films with strong anisotropy of the easy-plane type. The investigations have shown that, influenced by a current impulse passing through an antidot, an inhomogeneous magnetic structure is formed, which is accompanied by the localization of a quasiparticle with the +1 topological charge on the antidot and by an emission of a quasiparticle with a –1 charge. It is established that this scenario of the film magnetization reversal underlies a reformation of its inhomogeneous structure also if two or four antidots are present in the film, irrespective of the fact of through which antidots and in which directions the currents are passed. The results of the research obtained by using two independent methods (solving the Landau–Lifshitz–Gilbert equations and analyzing the lattice model) demonstrated good agreement between the two. It is shown that a magnetic film comprising two or four antidots can be used as a memory cell for recording data in the ternary system.

The paper investigates stability conditions of vortex-like inhomogeneities in perforated ferromagnet films with strong uniaxial anisotropy of the 'easy plane' type. It has been demonstrated that the non-trivial magnetic structures, which are characterized by the absence of an exit of the magnetization vector from the film's plane, can be observed at the absolute values of the anisotropy constant which exceed a certain threshold point. Possible methods (analytical, numeric, and empiric) have been developed to calculate this threshold value. Universally applicable estimates have been obtained of the minimum permissible value of the anisotropy constant for a number of the most important cases. Possible scenarios have been investigated for a loss of stability of the magnetic structure as the film's material parameters vary.