Interaction of a moving domain wall with surface magnetoelastic waves in yttrium orthoferrite

The amplitude-frequency characteristics of magnetoelastic surface waves excited by moving domain walls in a lamellar yttrium orthoferrite samples are discovered and measured. The results of analysis of the effect of magnetoelastic surface waves on the dynamics of domain walls in this orthoferrite are considered. The nonlinear interaction between magnetoelastic surface waves accompanying a moving domain wall is analyzed.     

Spin waves in a ferromagnet with a moving domain wall

An exact solution of the equation for spin waves propagating along the normal to the domain wall is derived for a ferromagnet with a 180° domain wall moving at constant speed, and the radiation of spin waves in rf fields is investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 66–69, April, 1979.     

Magneto-optical effects upon reflection of light from a ferrodielectric with an arbitrary orientation of magnetization

The boundary problem for a semi-infinite magnetic medium with arbitrary orientation of the magnetization vector is solved and polarization-and intensity-related characteristics of the reflected light wave are analyzed. It is shown that variations of the angle of incidence and of the orientation of the magnetization and polarization plane substantially affect the polarization characteristics of the reflected wave and give rise to specific features of the dependences under study.     

Interaction of a shear wave with a moving domain wall in an iron garnet crystal

The boundary-value problem of the interaction of a plane monochromatic shear wave with a moving Bloch wall in an iron garnet crystal is solved in the framework of the nonexchange magnetostatic approximation on the basis of the method of phase invariants for wave problems with moving boundaries. For a shear wave incident on the domain wall, the possibility of the reflectionless birefringence is demonstrated. Numerical results illustrating the resonance properties of the magnetic subsystem are presented. It is established that, at the upper bound of the reflectionless birefringence range, the interaction of the shear wave with the domain wall manifests itself as a degenerate resonance with the solution in the form of two combined antiphase, collinearly propagating shear waves of infinitely large amplitudes, which form a zero resulting field.     

Solitary flexural waves on a supersonic domain wall in yttrium orthoferrite

Solitary flexural waves on a supersonic domain wall in yttrium orthoferrite are observed and investigated. These waves have a sharp leading edge and a protracted trailing edge, reminiscent of the waves accompanying moving vertical Bloch lines in iron garnet films. The total velocity of the solitary flexural waves in yttrium orthoferrites for all observed amplitudes equals the maximum velocity of the domain walls. Two solitary waves with identical amplitudes colliding head-on are annihilated. The waves possess topological charges, and they move and form dynamic profiles under the influence of gyroscopic forces. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 10, 760–765 (25 May 1997)     

Interaction of ultrasonic waves with domain walls on nanocrystalline YIG

The nanocrystalline YIG samples with different particle sizes (20–40 nm) has been prepared using microwave–hydrothermal method. As synthesized powders were characterized using XRD and TEM. The powders were pressed and sintered at three different temperatures i.e., 700 °C/30 min, 800 °C/30 min, 900 °C/30 min, using microwave furnace. The sintered samples were characterized using XRD and TEM. The sintered samples are monophasic in nature with average grain size ranging in between 72 nm and 90 nm. The thermal variation of ultrasonic velocities [longitudinal (V_l) and transverse (V_S)] and longitudinal attenuation (α_l) has been measured on sintered samples by the pulse transmissionmethod at 1 MHz, in the temperature range of 300–600 K. The room temperature velocity is found to be grain size dependent and decreases with increasing temperature, except near the Curie temperature, T_C, where a small anomaly is observed. The longitudinal attenuation (α₁) at room temperature is also found to be more sample dependent. The temperature variation of ultrasonic longitudinal attenuation exhibits a sharp maximum just below Curie temperature (T_C). The above observations were carried on in the demagnetized state, on the application of a saturation field of 380 mT, the anomaly observed in the thermal variation of velocities (longitudinal and transverse) and attenuation is found to disappears. The observed interaction of ultrasonic velocity with domain walls has been qualitatively explained with the help oftemperature variation of magneto-crystalline anisotropy constant (k₁) and Landau’s theory.     

Interaction of space-charge waves in an electron beam with electromagnetic waves in a longitudinal magnetic field

The effect of space charge on the interaction between an electron beam and an electromagnetic wave in a longitudinal magnetic field has been considered. The equations describing the interaction processes have been formulated within the two-dimensional linear theory and solved using the dispersion-equation approach and the successive approximation method.     

Electroacoustic waves confined by a moving domain wall superlattice of a ferroelectric crystal

The dispersion properties of electroacoustic wave modes confined by a superlattice of uniformly moving 180° domain walls in a tetragonal ferroelectric crystal are considered. It is shown that the manifold of partial electroacoustic interfacial waves in the lattice is restricted to the first allowed band, the configuration of which in the plane of spectral variables can significantly vary under the action of the moving domain walls.     

Excitation of spin waves localized on a moving domain wall in a two-layer ferromagnetic film

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.     

Interaction of light waves on a reflecting holographic grating in cubic photorefractive crystals

The interaction of two antiparallel light waves on a reflecting grating is analyzed theoretically in arbitrarily oriented optically active cubic crystals of point group 23. The effect of nonunidirectional energy transfer on the interaction efficiency is investigated in the undepleted-pump-power approximation in (100)-, (111)-, and $(11\bar 2)$ -cut Bi₁₂TiO₂₀ crystals.     

Interaction of laser light waves by dynamic stark splitting

The internal stresses of condensed films are measured during both, condensation and annealing. Especially, materials are studied which can be stabilized in amorphous phases by quenching condensation technique. All amorphous films of Bi, Bi + Pb, Bi+Sb, Pb+Bi and Sn+Cu grow without any noticeable stress. In contrary, amorphous Sb-films arise with remarkable tensil stresses. The probably important difference between Sb and the other materials consists in the composition of the vapor. At normal evaporation conditions Sb-vapor contains almost only Sb₄-molecules, whereas the other materials evaporate monoatomically. The results are discussed with regard to a modell for the origin of the stresses based on the socalled Ostwald's rule for crystal growth.     

Interaction of light with acoustic waves excited by an inphase multielement transducer in the 1.0–2.5 GHz range

Interaction between a weakly divergent optical beam and an acoustic wave generated in the range 1.0–2.5 GHz by an inphase multielement electroacoustic piezoelectric transducer is analyzed. A piezoelectric (Y + 36°)-cut LiNbO₃ plate is fixed on the surface of an X-cut LiNbO₃ acoustic duct with the help of metallic sublayers (Cr, Cu, In, Cu, or Cr). The inphase structure of the transducer is formed by the upper electrodes inter-connected by short conductors. The signal is applied through a coaxial Chebyshev transformer. The efficiencies of electroacoustic conversion and acoustooptic interaction are calculated as functions of frequency. The experimental setup, method, and results are described.     

Interaction of a shear wave with a moving domain wall in a ferromagnetic crystal with allowance for the external magnetic field

The boundary-value problem of the magnetoelastic wave interaction with a moving domain wall in a ferromagnetic crystal is solved in the nonexchange magnetostatic approximation with allowance for the external magnetic field. It is shown that the difference introduced by magnetic field between the ferromagnetic resonance frequencies of the domains does not cause any noticeably departure of the refraction characteristics of reflected and transmitted waves from those observed at zero frequency mismatch. By contrast, the magnitudes of the transmission and reflection coefficients strongly depend on the external magnetic field and on the mobility of the domain wall. The dependence of the magnitude of the reflection coefficient on the external magnetic field at a fixed angle of shear wave incidence is found to possess two ferromagnetic resonance peaks. The positions and heights of the peaks may vary depending on the mobility of the domain wall.     

Solitary deflection waves on the supersonic domain wall in yttrium orthoferrite

The moving antiferromagnetic vortices are accompanied by solitary deflection waves. These waves allow to investigate generation and nonlinear dynamics of the antiferromagnetic vortices on the moving domain wall with the help of the two- and three-fold digital high speed photography. On the quasi-relativistic domain wall the vortex dynamics is quasi-relativistic with the limiting velocity c=20 km/s, which is equal to the spin-wave velocity. The solitary deflection waves dynamics can be explained assuming existence of the gyroscopic force. A theory for the gyroscopic force in the orthoferrite domain wall is elaborating by A.K. Zvezdin et al. currently. We present a comparison of the theoretical and experimental results on the dynamics of the solitary deflection waves, which accompany the antiferromagnetic vortices in the domain wall of orthoferrites.     

Interaction of molecules with a semiconductor wall

Summary In this paper we consider the interaction of vibrationally and electron-excited molecules with a wall made of a semiconductor with the widths of the forbidden zone close to the excitation energy of the molecules. It is shown that the main process induced by the collision of a molecule with such a wall is the production of an electron-hole pair. To speed up publication, the author of this paper has agreed to not receive the proofs for correction.     

Anomalous surface deceleration of a domain wall in an amorphous ferromagnet

On soft magnetic amorphous specimens, a rapid decrease in the surface amplitude of 180° domain wall oscillations relative to the bulk amplitude is observed with increasing frequency of the magnetizing field. The dynamics of the domain wall is studied by a magnetooptical method at the specimen surface and by the induction method in the bulk. The results of the experiment disagree with the theory, which takes into account the effect of eddy currents and predicts that, with increasing frequency, the surface amplitude of the domain wall oscillations should decrease slower than the bulk amplitude. The observed behavior of the domain wall is explained by its interaction with macroscopic defects at the specimen surface. This interaction gives rise to unsteady chaotic surface wall displacements, which lead to an increase by several orders of magnitude in the effective surface damping parameter in the Landau-Lifshits equation.     

Interaction of a three-mass system with gravitational waves

The interaction of a harmonically bound three-mass system with gravitational waves is analyzed in detail. The system resonantly responds to two polarization states of gravitational waves at a given frequency and transforms the two polarization states into two kinds of vibrations which can be clearly distinguished. The averaged cross section and maximum cross section also are given. As compared with a two-mass system under the same conditions, the three-mass system is at the maximum 1.2 times as large as the averaged cross section of the two-mass system, and its maximum cross section is at the maximum 1.5 times as large as that of the two-mass system.     

Interaction of light waves in active nonlinear and periodically poled nonlinear crystals

The results of classical and quantum studies of the laser-radiation self-frequency conversion processes in periodically poled active nonlinear crystals are overviewed. The theoretical and experimental results of studying quasi-phase-matched self-frequency doubling and summation of the laser and pump frequencies in an active nonlinear periodically poled Nd:Mg:LiNbO₃ crystal are presented. The possibility of producing frequency-and polarization-entangled states and the sub-Poisson field statistics through a consecutive nonlinear optical frequency conversion in periodically poled nonlinear crystals is considered.