The motion of an isolated domain wall in bilayer uniaxial magnetic films with a gyromagnetic ratio of different sign in the layers is studied by numerically solving the Slonczewski equations. The gyromagnetic ratio and the thickness of the layers are varied, and threshold values of the field and velocity of the domain wall at which a breakdown of its stationary motion takes place are calculated. It is shown that, for a specific relationship between the thickness and the gyromagnetic ratio of the layers, the field and the velocity for the breakdown of the stationary motion of the domain wall increase infinitely.

Single-crystal gadolinium gallium garnet films have been grown by liquid-phase epitaxy on (111) Gd3Ga5O12 substrates from supercooled Bi2O3-B2O3 fluxed melts at different Gd2O3 concentrations. The luminescence spectra of the films have been measured at 10 and 300 K under unmonochromatized synchrotron X-ray excitation and selective UV synchrotron excitation. The Bi3+ luminescence is discussed.

The excitation spectrum of spin waves localized on a domain wall in a two-layered uniaxial ferromagnetic film has been investigated with allowance for the demagnetizing field of the film. A resonance behavior of the excited standing spin waves has been revealed.

The stray magnetic fields of rock samples with inclusions of the magnetic grains and magnetic crystals were observed using epitaxial (Bi,Lu)3(Fe,Ga)5O12 films with uniaxial magnetic anisotropy. Basalt rocks with inclusions of titano-magnetite and native elsen but also crystals of titano-magnetite and pyrrhotin were investigated. Stray magnetic fields were visualized with the Faraday Effect.

Теоретически исследован спектр возбуждения спиновых волн, локализованных на доменной стенке в двухслойной одноосной ферромагнитной пленке с учетом поля размагничивания пленки. Обнаружено резонансное поведение возбуждаемых стоячих спиновых волн.

The motion of an isolated domain wall in a two-layered uniaxial magnetic film has been investigated by solving Slonczewski equations by the progonka method with allowance for the demagnetizing fields of the layers. Perpendicular to the plane of the domain wall, there was applied an in-plane external magnetic field, whose intensity was varied. Static configurations of a twisted domain wall have been calculated. In the dependence of the domain-wall velocity on the magnetic field applied along the normal to the film plane, additional maxima have been revealed in the range of middle fields. The dependences of the position of the domain wall and of the phase angle on the time and the coordinate along the normal to the film plane have been calculated.

The problem of excitation of spin waves in a two-layer magnetic film with a sharp interface between the layers is solved on the basis of Slonchevskii equations. The equations describing spin wave excitation along the film thickness are derived. The results are limited to zeroth approximation in the smallness parameter ɛ, viz. the ratio of the energy of magnetic dipole forces to the anisotropy energy. The power dissipated by such oscillations is calculated.

We have studied the effect of Pb2+ impurities and Pb2+-Pb4+ pairs on the optical absorption between 200 and 860 nm in single-crystal gadolinium gallium garnet films grown by liquid-phase epitaxy from supercooled PbO-B2O3 fluxed melts containing 0.1–0.5 mol% gadolinia.

Single-crystal films of complex composition (Bi, Gd)(3) (Ga, Pt)(2) Ga-3 O-12 on Gd-3 Ga-5 O-12 (111) substrates are synthesized by liquid- phase epitaxy from a supercooled solution - melt based on Bi2O3 - B2O3 flux. Optical absorption of Bi3+ and Pt3+ ions in these films is investigated in the wavelength range from 200 to 860 nm.

Motion of an isolated domain wall in a double-layer uniaxial magnetic film, where the film layers differ in characteristic length, saturation magnetization and damping parameter, is investigated by solving the Slonczewski equation. A planar magnetic field is applied normal to the domain-wall plane. The dependences of the threshold field and limiting velocity of disruption of the steady-state motion of the domain wall on the planar magnetic field value are obtained.

Single-crystal films of complex composition (Bi,Gd)3(Ga,Pt)2Ga3O12 on Gd3Ga5O12(111) substrates are synthesized by liquid-phase epitaxy from a supercooled solution-melt based on Bi2O3-B2O3 flux. Optical absorption of Bi3+ and Pt3+ ions in these films is investigated in the wavelength range from 200 to 860 nm.

Gadolinium gallium garnet single-crystal films containing terbium are grown through liquid-phase epitaxy from a supercooled solution melt in the PbO-B 2 O 3 system. The optical absorption spectra in the wavelength range 0.2–10.0 μm and the luminescence spectra excited by synchrotron radiation with energies in the range 3.5–30.0 eV are investigated at temperatures of 10 and 300 K. It is revealed that the optical absorption spectra contain an absorption band with the maximum at a wavelength λ ≈0.260 μm, which corresponds to the spin-allowed electric dipole transition between the electronic configurations 4 f 8 ( 7 F 6 ) → 4 f 7 ( 8 S )5 d of the Tb 3+ ions. The narrow low-intensity absorption bands attributed to the 4 f → 4 f transitions from the 7 F 6 ground level to the 7 F 0–5 multiplet levels of the Tb 3+ ions are observed in the wavelength range 1.7–10.0 μm. In the luminescence spectra measured at a temperature of 10 K, the highest intensity is observed for a band with the maximum at a wavelength λ ≈ 0.544 μm, which is associated with the 5 D 4 → 7 F 5 radiative transition in the Tb 3+ ion.

Motion of an isolated domain wall in two-layer uniaxial magnetic films with the same gyromagnetic ratios in the layers is investigated by solving the Slonczewski equations using a numerical method. The steady-state motion regimes are established for the domain with the angle of magnetization vector departure from the wall plane exceeding π.

It is shown that the ferromagnetic resonance spectrum in (Bi,Tm)3(Fe,Ga)5O12 films grown in Gd3Ga5O12(210) substrates has a single peak. The azimuthal and polar dependences of the resonance field possess 180° symmetry. The angular dependences of the ferromagnetic resonance line width and intensity are studied.

The phosphorescence of a Gd 3 Ga 5 O 12 single crystal grown by the Czochralski method is discussed. The phosphorescence was excited by UV radiation of a deuterium lamp.

Numerical solution of the Slonczewski equations were used to study the motion of an individual domain wall in a two-layer uniaxial film in which the damping parameter and the gyromagnetic ratio depend on the specific layer.

Single crystals of gadolinium-containing garnets with the compositions Gd3Ga5O12, Gd3(Sc,Ga)5O12:Cr, and (Gd,Ca)3(Mg,Zr,Ga)5O12 were grown using the Czochralski technique, and their luminescence was studied under the conditions of excitation with “white” synchrotron radiation. The observed differences in the luminescence spectra are discussed.