A contribution to the domain structure of iron whiskers

The paper contains an interpretation of the domain patterns found on iron whiskers. An explanation of the closure structure at the end of a whisker grown in the [111] direction is given on the basis of a quantitative analysis. Structures, which form on whiskers strained by axial pressure and bending, are also dealt with. The results are in good agreement with experiment.

---

, . [111]. , . .

     

Domain structure of Fe-N alloy

Observations of domain structures in single crystal and polycrystalline samples of Fe-N alloy were made. It was found that the magnetization direction is perpendicular to the surface of Fe₁₆N₂ nitrides. The domain structure is not subject to essential changes during ageing.     

Domain structure of cellulose triacetate

The topology of the surface of thin films obtained from cellulose triacetate solutions has been studied using electron microscopy. The domain structure of the physical network of macromolecules (percolation cluster) with the maximum size L ≈ 30 nm of regions with a local orientational order has been established. With an increase in the volume fraction Ω of the cluster to the critical value Ω = 0.91, repacking of domains takes place, which is connected with a decrease in the parameter Ω, L doubling bifurcation of the size L, and formation of regions of long-range orientational order: the mesophase of the polymer.     

The electronic structure of cobalt phthalocyanine

The electronic structure and morphology of organic semiconducting cobalt-phtalocyanine (CoPc) films in situ prepared on the Au(001)-5×20 superstructure have been studied by a combination of experimental and theoretical work. The CoPc molecular film was characterized by photoemission spectroscopy (PES, valence band and core-level). The experimental results were simulated and have been explained in the framework of density functional theory (DFT) calculations. The C 1s and N 1s core level spectra were analyzed by taking into account the fact that both types of atoms have different nonequivalent positions in the molecule. And finally, the experimentally obtained electronic valence band structure of CoPc is in very good agreement with ab initio density of state results, allowing a detailed site-specific insight into the system.     

Electronic structure of cobalt disilicide film

The electronic structure of cobalt disilicide film has been investigated theoretically. The calculations are performed within the framework of the linearized augmented plane wave method. A combined analysis of the total and local partial densities of states and the photoelectron and x-ray emission spectra of different series for all the nonequivalent atoms of the film makes it possible to interpret the main features of the spectral characteristics of this material.     

Domain structure in centroantisymmetric antiferromagnets

The domain structure of an antiferromagnet whose magnetic-symmetry group contains a center of antisymmetry is studied theoretically. The magnetoelectric effect and weak ferromagnetism are shown to coexist in a domain wall. It is established that when the inhomogeneous magnetic moment interacts with a sufficiently strong magnetic field H ‖ C ₃, a multidomain state with an odd number of 180° domain walls becomes energetically favorable. The critical field for the transition from a single-domain state to a multidomain state is found. It is shown that domain reversal occurs when the magnetic field H is reversed.     

Domain structure in ferroelectric-ferromagnetic films

The conditions for the phase transition to the ferroelectromagnetic phase in ferroelectric-ferromagnetic films through the mechanism of the loss of stability of the initial homogeneous state have been considered. The geometry of the domain structure and the temperature of the transition to the inhomogeneous state have been determined. The condition for the phase transition to the ferroelectromagnetic phase has been established and determined by the relationship between the temperature-dependent coefficients of the expansion of the thermodynamic potential into a series in terms of the polarization and magnetization vector components. The influence of free charge carriers on the geometry of the domain structure and the transition temperature has been studied. The possible existence of a single-domain state has been discussed. The permittivity of a multidomain sample has been determined. The feasibility of exploiting the studied material for nondestructive recording and reading of information has been noted.     

Domain structure of a tetragonal antiferromagnet

A theory of the 90° and 180° domain structure in an easy-plane tetragonal antiferromagnet with nonuniform internal magnetostrictive and mechanical stresses has been developed. The reconstruction of domain structure in an external magnetic field was investigated. Dependencies of critical fields of stability loss of the 90° and 180° domain structures upon a directional external pressure, and magnetostrictive and nonuniform mechanical stresses have been determined. The dependence of the magnetization curve on mechanical stresses has also been determined.     

磁性钴纳米晶的二维自组装

在两种表面活性剂存在下，采用高温醇还原，合成出单分散、平均颗粒尺寸为14±19nm，直径标准偏差小(～18%)的磁性金属Co纳米晶.利用x射线衍射、紫外吸收光谱、x射线光电子能谱及透射电子显微镜对其结构和表面价态进行了分析.并将磁性金属Co纳米晶自组织形成有序的二维(2D)六方紧密堆积结构. 关键词： Co纳米晶 单分散 自组装     

Domain structure in a superconducting ferromagnet

The domain structure is inherent to all ferromagnets and the recent discovery of the superconducting ferromagnets raises the question of the modification of this domain structure by superconductivity. In the framework of the general London theory, applicable to both singlet and triplet superconductors, we demonstrate that superconductivity leads to a dramatic shrinkage of the domain width. The presence of this dense domain structure has to be taken into account for all magnetic measurements on superconducting ferromagnets, and the study of the domain structure evolution could provide important information on the mechanisms of superconductivity and magnetism interplay.     

Domain structure of silicon iron single crystals

The model of a new domain structure arising after the magnetization of silicon iron single crystals in planes of the (110) type at an angle of 0°<Θ<-55° to the axis of easy magnetization is considered. Using this model the angular dependence of the domain-structure characteristics is established; it agrees closely with direct observations. On magnetizing a single crystal in the angular range 55° <Θ≤ 90° to the easy axis, layers with a uniform resultant magnetization parallel to the [001] direction are formed.     

Influence of magnetostriction on the domain structure of cobalt

The paper presents the calculation of the energy of elastic stresses in the domain structure of uniaxial massive ferromagnetics. The inclusion of this energy permits the formation of a structure with walls perpendicular to the external field to be elucidated and the critical thickness of the sample on which this structure is realized to be determined.     

Domain structures of crystals of cobalt and magnetoplumbite in the residually magnetized and demagnetized states

A strong field perpendicular to the [0001] axis produces a layered domain structure, the domain boundaries being perpendicular to the field [1–3]; this is not explained by the theory, which indicates [4, 5] that the best position is with the boundaries parallel to the field. The latter has been observed [6–9] for thin magnetically uniaxial crystals when the field is at 70^* to [0001], whereas a honeycomb structure occurs in these specimens when the field is perpendicular to [0001]. The causes of these effects have been examined by reference to the action of the field direction relative to the hexagonal axis on the domain structure. A similar problem has been considered [6–9] for crystals a few microns thick.