共查询到20条相似文献,搜索用时 62 毫秒
1.
A new physical effect, namely, oscillations of the orbital magnetic moment with a change in the electric field strength in
two types of nanostructures, has been predicted. Explicit analytical expressions for the orbital magnetic moment of a quantum
well and a quantum dot in crossed magnetic and electric fields have been derived. The oscillations of the orbital magnetic
moment with a change in the electric and magnetic fields have been studied. The oscillation periods in both the electric and
magnetic fields have been found and the limiting cases of the strong magnetic and quantum confinement effects have been considered. 相似文献
2.
A. V. Chzhan S. Ya. Kiparisov V. A. Seredkin G. S. Patrin M. G. Pal’chik 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(8):1161-1163
The magnetic properties of a film trilayer consisting of hard magnetic and soft magnetic Co-P layers separated by a nonmagnetic
Ni-P spacer have been studied. The features of the hysteresis shift relative to the zero exchange magnetic field and of the
coercivity of the soft magnetic layer in the dependence on thicknesses of the hard magnetic layer and spacer have been considered.
The dynamic changes in the shift of the hysteresis of the soft magnetic layer versus the magnetization reversal time after
saturation of the hard magnetic layer have been found and investigated. 相似文献
3.
《Photonics and Nanostructures》2014,12(5):473-481
Electrodynamic properties of the graphene–magnetic semiconductor–graphene sandwich-structure have been investigated theoretically with taking into account the dissipation processes. Influence of graphene layers on electromagnetic waves propagation in graphene–semi-infinte magnetic semiconductor and graphene–magnetic semiconductor–graphene sandwich-structure has been analyzed. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such structure have been calculated. The size effects associated with the thickness of the structure have been analyzed. The possibility of efficient control of electrodynamic properties of graphene–magnetic semiconductor–graphene sandwich-structure by an external magnetic field has been shown. 相似文献
4.
会切磁场中大回旋电子束产生的研究 总被引:1,自引:0,他引:1
研究了会切磁场产生的机理。通过对Moster-Molnar 模型的探讨, 建立了会切磁场的物理模型。在会切磁场理论分析和数值模拟基础上, 探讨了影响会切磁场设计的因数; 利用拉格朗日公式求解了会切磁场中电子运动轨迹。探讨了会切磁场与大回旋空心会切电子枪的关系, 得到了改进会切电子枪性能的一些一般性结论。 相似文献
5.
A combined effect of laser treatment and introduced fine-grained weakly magnetic impurity Mg–P–B defects on the magnetic structure and physical properties of anisotropic electrotechnical materials has been investigated. Specific features of changes in the type and behavior of the magnetic domain structure under different types of deformation (laser irradiation, scratching, and introduction of interstitial defects) have been revealed. The physical basis and optimum conditions of increase in thermal stability of local laser treatment zones in soft magnetic alloys have been determined. The obtained results open the prospects of decreasing magnetic losses in soft magnetic alloys and producing magnetic materials with a high level of physical and mechanical properties that are more resistant to operating conditions. 相似文献
6.
E. I. Kurek I. G. Kurek A. V. Oleinich-Lysyuk N. D. Raranskii 《Physics of the Solid State》2014,56(8):1597-1604
The behavior of the effective shear modulus and low-frequency internal friction in magnesium-thermal beryllium condensate before and after the treatment of samples in a weak constant magnetic field has been studied. The data obtained have been used for calculating the temperature and time dependences of the ratio between the dislocation motion velocities during and after the magnetic action. It has been shown that the exposure of samples to a magnetic field and their aging after the magnetic action radically change the character of the temperature dependences of the dislocation motion velocities. Empirical expressions describing these dependences have been obtained. It has been demonstrated that the magnetic aftereffect in diamagnetic beryllium has a complex character, which indicates the presence of several magnetic memory mechanisms. 相似文献
7.
A. Laurinaviius P. Malakauskas K. Pozela 《International Journal of Infrared and Millimeter Waves》1988,9(4):371-384
The peculiarities of the microwave radiation through the semiconductor wall of the rectangular metallic waveguide set in the external magnetic field have been investigated. The radiation direction dependence on wave frequency, the external magnetic field, and the geometric shape of the semiconductor element have been determined. It has been shown that in the case of the wedge-like semiconductor element the radiation direction can be controlled by the external magnetic field. The experiments have been carried out in V-band at the temperature of liquid nitrogen. 相似文献
8.
D. A. Klimachkov A. S. Petrosyan 《Journal of Experimental and Theoretical Physics》2017,125(4):597-612
We have studied rotating magnetohydrodynamic flows of a thin layer of astrophysical plasma with a free boundary in the β-plane. Nonlinear interactions of the Rossby waves have been analyzed in the shallow-water approximation based on the averaging of the initial equations of the magnetic fluid dynamics of the plasma over the depth. The shallow-water magnetohydrodynamic equations have been generalized to the case of a plasma layer in an external vertical magnetic field. We have considered two types of the flow, viz., the flow in an external vertical magnetic field and the flow in the presence of a horizontal magnetic field. Qualitative analysis of the dispersion curves shows the presence of three-wave nonlinear interactions of the magnetic Rossby waves in both cases. In the particular case of zero external magnetic field, the wave dynamics in the layer of a plasma is analogous to the wave dynamics in a neutral fluid. The asymptotic method of multiscale expansions has been used for deriving the nonlinear equations of interaction in an external vertical magnetic field for slowly varying amplitudes, which describe three-wave interactions in a vertical external magnetic field as well as three-wave interactions of waves in a horizontal magnetic field. It is shown that decay instabilities and parametric wave amplification mechanisms exist in each case under investigation. The instability increments and the parametric gain coefficients have been determined for the relevant processes. 相似文献
9.
Dynamic regimes of a magnetic moment of 2 × 2, 3 × 3, and 4 × 4 square dipole lattices in the linearly and circularly polarized ac magnetic field and the perpendicular static field have been investigated. The possibility of regular and chaotic precession dynamics of the magnetic moment of the lattices has been demonstrated. A shift of the main magnetic resonance owing to the dipole–dipole interaction and additional resonances have been revealed. Quasiperiodic regimes and bistability states with a metastable chaotic attractor have been discovered. 相似文献
10.
《Journal of magnetism and magnetic materials》1987,67(1):49-54
The magnetic field induced magnetic phases of EuAs3 have been studied with neutron diffraction. Five different magnetic structures have been identified by their moment directions and propagation vectors, only one of them being commensurate with the crystallographic lattice. The change of the magnetic structures with increasing field gives some information on the magnetic exchange interactions. 相似文献
11.
Disordered alloys of magnetic atoms of two types have been considered within the Ising model based on the calculation and analysis of the distribution function of effective fields acting on magnetic atoms. The Curie temperatures, magnetizations of two magnetic “sublattices,” threshold concentrations of magnetic atoms, and magnetic phase diagrams of alloys have been calculated. 相似文献
12.
M. V. Kozintseva A. M. Bishaev A. A. Bush M. B. Gavrikov K. E. Kamentsev N. A. Nizhel’skii V. V. Savel’ev A. S. Sigov 《Technical Physics》2017,62(6):890-894
The properties of short-circuited multiturn superconducting coils have been studied; coils with nonsuperconducting contacts have been fabricated from a high-temperature superconducting (HTSC) tape made by Super Power Company. The magnetic flux captured by HTSC coils has been measured at different values of magnetic field of the magnetizing solenoid. the critical current in the coils have been experimentally determined based on the maximum values of the field they captured. It is ~50% of the nominal value for this HTSC tape. The range of external magnetic field, where HTSC coils keep the captured magnetic flux, has been experimentally found. The obtained results have demonstrated the possibility of designing magnet systems with levitating coils made of HTSC tape, in which levitation is controlled without using feedbacks. 相似文献
13.
General equations governing the stability of stratified fluid in a stratified porous medium in the presence of suspended particles and variable horizontal magnetic field, separately, have been derived. Assuming stratifications in density, viscosity, suspended particles number density, medium porosity, medium permeability and a magnetic field of exponential form the dispersion relations have been obtained. Systems have been found to be stable for stable stratifications and unstable for unstable stratifications. A system which was unstable in the absence of magnetic field can be completely stabilized by a magnetic field for a certain wave-number range. The behaviour of growth rates with respect to fluid viscosity, medium permeability, suspended particles number density and magnetic field has been examined analytically. 相似文献
14.
V. N. Nikiforov A. N. Ignatenko V. Yu. Irkhin 《Journal of Experimental and Theoretical Physics》2017,124(2):304-310
The size effects of magnetite and maghemite nanoparticles on their magnetic properties (magnetic moment, Curie temperature, blocking temperature, etc.) have been investigated. Magnetic separation and centrifugation of an aqueous solution of nanoparticles were used for their separation into fractions; their sizes were measured by atomic force microscopy, dynamic light scattering, and electron microscopy. A change in the size leads to a change in the Curie temperature and magnetic moment per formula unit. Both native nanoparticles and those covered with a bioresorbable layer have been considered. The magnetic properties have been calculated by the Monte Carlo method for the classical Heisenberg model with various bulk and surface magnetic moments. 相似文献
15.
The size-dependent magnetic properties of small iron clusters deposited on ultrathin nickel films have been studied with circularly polarized synchrotron radiation. With the use of sum rules, orbital and spin magnetic moments have been extracted from x-ray magnetic circular dichroism spectra. The ratio of orbital to spin magnetic moments varies considerably with cluster size, reflecting the dependence of magnetic properties on cluster size and geometry. These variations can be explained in terms of enhanced orbital moments in small clusters. 相似文献
16.
A. Sargsyan R. Mirzoyan T. Vartanyan D. Sarkisyan 《Journal of Experimental and Theoretical Physics》2014,118(3):359-364
The splitting of hyperfine sublevels of the 85Rb atom in strong magnetic fields has been studied by means of the coherent population trapping technique. Narrow resonances with a high signal-to-noise ratio have been detected in a 30-μm-thick spectroscopic cell. The magnetic field in the direction transverse to the laser beams has been created by permanent magnets and has reached 1600 G. Owing to the exclusive narrowness of the cell, the field in it is almost uniform. The break of the coupling between the electronic and nuclear moments, as well as the transition to the Paschen-Back regime in magnetic fields above 600 G, has been observed. The derivatives of the frequency shifts of the observed resonances and their asymptotic values in strong magnetic fields have been determined in terms of the magnetic field strength. The experimental results have been interpreted within a theoretical model based on the known constants of the hyperfine structure of the Rb atom. 相似文献
17.
New magnetic structures such as multilayer systems of magnetic nanoislands being alternating layers of nanoislands of various magnets have been proposed. The electric, magnetic, and magnetooptical properties of the systems have been studied. The magnetoresistance of ~2% related to the anisotropic effect has been revealed. In multilayer structures of magnetic nanoislands, a unidirectional axis of predominant magnetization has been found, which changes its orientation depending on the structure parameters. The magnetic field required to reorient the axis in the opposite direction has been estimated to be 2 kOe < H A < 20 kOe. The periodic multilayer structures of magnetic nanoislands are very sensitive to hyperweak magnetic fields (to 10?6 Oe). 相似文献
18.
V. M. Amoskov A. M. Bazarov V. A. Belyakov E. I. Gapionok M. V. Kaparkova V. P. Kukhtin E. A. Lamzin B. V. Lyublin D. A. Ovsyannikov S. E. Sytchevsky 《Technical Physics》2017,62(10):1466-1472
We have proposed an effective method for modeling the steel reinforcement in the buildings for electrophysical devices to take into account the magnetic field perturbation caused by the magnetization of bars. The reinforcement lattice has been represented by one or several layers of a homogeneous isotropic material with preliminarily calculated equivalent (averaged) magnetic properties. Examples of calculating these magnetic properties have been considered using a simplified analytic approach, as well as by the numerical simulation of the magnetic field in a 3D cell of a periodic reinforcement lattice. The efficiency of the method has been demonstrated based on an important practical example of simulating the perturbation of a uniform magnetic field caused by the reinforced slab. The results have been compared with the simulation data based on different approaches. 相似文献
19.
Hydromagnetic turbulent shear flow of viscous, incompressible, electrically conducting fluid between two infinite uniformly porous moving parallel planes in the presence of axial and transverse magnetic field has been studied by the semi-empirical method. The expressions for the mean distributions for velocity and magnetic field for turbulent shear flow have been obtained for both the cases. As particular cases, the results have been obtained if the planes are fixed. The solutions obtained when the magnetic field is axial have been shown graphically for turbulent and laminar flows. 相似文献
20.
The equilibrium states of annular systems of magnetic dipoles have been studied by computer simulation. The bistability conditions under which the total magnetic moment of one of equilibrium configurations is zero, while the magnetic moment of another equilibrium configuration lies in the ring plane and is close to the sum of the magnetic moments of dipoles in the system, have been determined. The realization of other equilibrium configurations has also been demonstrated. We analyze transitions between equilibrium configurations by acting on the system by longitudinal and circular static fields, as well as transitions from the configuration with the maximal magnetic moment of the system to the configuration with zero total magnetic moment after the relaxation of oscillatory regimes excited by a varying field. 相似文献