SU1513515A1 - Method of measuring non-homogeneity of domain-containing film - Google Patents

Abstract

The invention relates to computing and can be used in the development of magneto-optical controlled conveyors. The aim of the invention is to improve the measurement accuracy by determining the saturation magnetization distribution over the cell area. Local diffusion annealing iron garnet films in the presence of a reducing agent leads to a redistribution of nonmagnetic ions substitute iron, between tetrahedral and octahedral sublattices in the garnet structure, thus considerably varies saturation magnetization 4φM and the uniaxial anisotropy constant K and specific Faraday rotation Θ _F practically do not change. As a result, the effective uniaxial anisotropy field H _K = 2K / M changes. Since diffusion annealing is local, the magnetization distribution is non-uniform both in the film thickness and in the cell diameter.

Description

The invention relates to computing and can be used in the development of magneto-optical controlled conveyors.

The purpose of the invention is to improve the accuracy of measurement by determining the distribution of the saturation magnetization over the area of the cells.

In accordance with the proposed method, measurement of the heterogeneity of the domain-containing film with a cellular structure obtained by local diffusion annealing in the presence of a reducing agent is carried out in the following way.

The domain-containing film is magnetized to saturation and is affected

A pulsed magnetic field of reverse polarity with a variable amplitude, directed perpendicular to the film plane, and plane-polarized light is recorded on it. The process of pulsed reloading of the cells by rotation of the magnetization and the angle of rotation of the polarization plane of the light passing through the domain-containing film is recorded. the area of the cells and the location of the boundary of the magnetized region at the beginning of the process of pulsed magnetisation of the cells by rotating the magnetization at different amplitudes of the pulses The magnetic field is judged on the distribution of the saturation magnetization over the cell area.

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The essence of the invention is as follows. Local diffusion annealing iron garnet films in the presence of a reducing agent leads to a redistribution of nonmagnetic ions substitute iron, and between tetrazdricheskoy octahedral sublattices in the garnet structure, thus considerably varies nasscheni the magnetization M and the uniaxial anisotropy constant K and specific Faraday the rotation 0p is almost unchanged. As a consequence, the effective field of uniaxial anisotropy H, 2K / M changes. Since diffusion annealing is local, the magnetization distribution is non-uniform both in the film thickness and in the cell diameter.

As experience shows, when pulsed magnetization reversal of ferrite garnet films from the high-grade state is exceeded by the active field (the effective field of uniaxial anisotropy is realized by the mechanism of magnetization reversal by magnetization, and this mechanism is the fastest. Remagnetization occurs in the domain containing the film for which, and the regions with H j 7 N remain non-magnetized. Consequently, the location of the Genius of the boundary of the magnetized region at the beginning of the process of pulsed magnetization reversal by agility corresponds to the surface on which the local value I is equal to the declining field N. The depth of the surface of this surface in the cell can be determined by measuring the angle of rotation of the polarization of the light transmitted through the domain-containing film of light at different points on the cell area. surfaces corresponding to different values of P. Since K and 0p are not dependent on the character of the distribution of nonmagnetic ions between the garnet sublattices, the proposed method makes it possible to determine aspredelenie saturation magnetization of the domain-io cell area of the film.

II p and me. The proposed method was implemented on the well-known installation of high-speed photography. A source of plane-polarized light was a pulsed dye laser pumped by a pulsed nitrogen laser synchronized with a source of a pulsed magnetic field. Remaking of the cells was recorded in a known manner. The pulsed magnetic field had a rise time of 10 ns and a maximum amplitude. The ferrite-garnet film (Li, B1) 3 (Fe-, Ga) 50, was investigated. The cells had a diameter of 150 microns. Experience has shown that the value of 4 if M in film thickness changes by 30 Gs, and in diameter by 120 Gs, with the most dramatic change of 41Gm occurring in an area of 5–15 µm wide, and the boundary of cells is somewhat inclined with respect to the normal to film plane.

Claims (1)

Invention Formula A method for measuring the heterogeneity of a domain-containing film with a cellular structure obtained by local diffusion annealing in the presence of a reducing agent, based on. magnetizing the domain-containing film up to 1; Eni and exposure to a pulsed magnetic field of opposite polarity with a variable amplitude, directed perpendicular to the film plane, characterized in that, in order to improve the measurement accuracy by determining the magnetization distribution. During the action of a pulsed magnetic field, a domain-containing film is affected by plane-polarized light, the beginning of the process of pulsed magnetization reversal of the cells by rotating the magnetization and the angle of rotation of the polarization plane passing through the cell-containing film - the magnetized area at the beginning of the process of pulsed magnetization reversal by rotating the magnetization at different amplitudes of pulsed magnesium In this case, the distribution of saturation magnetization over cell area is judged.