Polymorphism of biperiodic stripe domain structures

Magnetic-field-induced polymorphism of biperiodic stripe domain structures of films with a positive anisotropy constant and easy axis parallel to the normal to the surface is studied. A symmetry classification of the observed types of domain structures is performed, and the phase diagram of the films in the (H _⊥, H _∥) plane, where H _⊥ and H _∥ are, respectively, the components of the magnetic field vector perpendicular and parallel to the normal to the surface, is determined. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 9, 701–706 (10 May 1998)     

Order-disorder-order phase transitions between metastable modifications of biperiodic stripe domain structures

Magnetooptic methods were used to observe the existence of magnetic-field-induced order-disorder-order phase transitions between metastable modifications of biperiodic stripe domain structures in magneto-uniaxial iron garnet films having a low positive anisotropy constant. It is shown that the loss of long-range order in the system in a certain range of variation of the field is caused by the loss of correlation between the quasi-harmonic surface distortions of the profile of neighboring domain walls.     

Induced unidirectional anisotropy and biperiodic stripe domain structures in magnetic films of subcritical thickness

JETP Letters - The existence of biperiodic stripe domain structures in the vicinity of the lines of orientational phase transitions has been found experimentally in uniaxial films of magnetic...     

Transformation of Hybrid Transverse Elastic Waves in Nonuniform Micropolar Media

Acoustical Physics - The features of propagation of coupled hybrid transverse elastic waves in a nonuniform dense micropolar medium with spatial dispersion are studied. It is shown that in the...     

Fourier images of fractal objects

Fourier images corresponding to diffraction patterns in the Fraunhofer zone were obtained for a set of fractal objects by means of computer simulation with the use of net functions. The fractal dimensions of the objects being investigated were determined on the basis of the intensity distribution in the diffraction patterns.     

Spontaneous phase transitions in magnetic films with a modulated structure

The influence of monoperiodic and biperiodic bias fields on the nucleation of domain structures in quasi-uniaxial magnetic films near the Curie point has been studied experimentally. The main types of observed nonuniform magnetic moment distributions have been established and chains of a devil’s staircase phase transitions are shown to be realized when the films are slowly cooled.     

Amorphization of biperiodic domain structures in quasi-uniaxial magnetic films with a critical thickness

The behavior of biperiodic stripe domain structures in quasi-uniaxial magnetic films with a near-critical thickness is studied by scanning magnetic force microscopy and magnetooptical diffraction. In these films, antiphase and hybrid biperiodic domain structures are found to be absent, and the phase transitions between monoperiodic and in-phase biperiodic domain structures are shown to proceed through two-dimensional domain arrays that are amorphized in the arrangement of near-surface distortions in the domain-wall profile.     

Phase diagrams of stratified bismuth–praseodymium-containing iron garnet films in an external magnetic field

The form of phase diagrams has been determined for epitaxial magnetic films of the composition Y_3–x–y Bi _x Pr _y Fe₅O₁₂ on the plane (H _‖ H _⊥), where H _‖ and H _⊥ are the external magnetic field components parallel and orthogonal, respectively, to the direction of the normal n to the surface of the film. The specific features have been revealed in the magnetization reversal of the objects under investigation, which are associated with their structural stratification.     

Phase transitions in biperiodic stripe domain structures of uniaxial magnetic films with a positive anisotropy constant

New phase transitions induced by a magnetic field and accompanied by a change in the symmetry or the period of the distribution of the magnetization vector are observed in biperiodic stripe domain structures of iron garnet films with a positive anisotropy constant. A symmetry classification of the observed types of domain structures is derived, and the form of the state diagram of the films is determined in the H∥H⊥ plane, where H∥ and H⊥ are the components of the magnetic field vector perpendicular and parallel to the normal to the surface. Zh. éksp. Teor. Fiz. 114, 2089–2110 (December 1998)