Device and method for detecting force thermal magnetic coupling action of ferromagnetic thin film

Abstract

The invention relates to a device and a method for detecting a force thermal magnetic coupling action of a ferromagnetic thin film, and belongs to the technical fields of engineering materials, structure deformation and mechanical experiments. The device comprises a ferromagnetic thin film uneven stress measuring optical circuit, a film magnetic hystersis loop measuring optical circuit, a Helmholtz coil and a power supply thereof, a test piece heating table, a thermocoupler, a force loading structure and an adjusting bracket. The film uneven stress measuring optical circuit comprises a laser, a beam expander, a spectroscope, a reflector, a raster, a lens, a filtering screen and a CCD camera; and the film magnetic hystersis loop measuring optical circuit comprises a laser, a beam expander, a reflector, a polarizer, a polarization analyzer and a photodetector. The method utilizes the Helmholtz coil to provide an even magnetic field for the ferromagnetic thin film, utilizes the test piece heating table to heat the film, utilizes the force loading structure to carry out force loading on the film, utilizes shearing interference to measure uneven curvature of the surface of the film and further obtain the stress of the film through the curvature, and utilizes Kerr magnetooptical effect on the surface of the ferromagnetic thin film to measure a magnetic hystersis loop of the film.

Description

technical field [0001] The invention relates to a detection device and method for the force-thermo-magnetic coupling behavior of a ferromagnetic thin film, and belongs to the technical fields of engineering materials, structural deformation and mechanical experiments. Background technique [0002] Ferromagnetic thin film material is a very important functional material in microelectronics and information technology. It has been widely used in many aspects. Under normal circumstances, the mechanical properties of ferromagnetic thin films often determine the usability and reliability of various devices prepared by it. When ferromagnetic thin films are subjected to stress (this stress can be mismatch strain, residual stress, external load or caused by the temperature change of the film), the microstructure of the film, that is, the crystal structure will change, and this change will affect the spin-orbit coupling of atoms or ions. If the change of the external magnetic field a...

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Problems solved by technology

[0007] where σ (f) is the membrane stress, E s , v s Respectively, the elastic modulus and Poisson's ratio of the matrix, h f , h s are the thickness of the film and the thickness of the substrate, respectively, and κ is the curvature of the film matrix structure obtained through experimental measurement. However, the uniform stress distribution of the film can only be obtained from the curvature using the Stoney formula. Therefore, more accurate analysis and more realistic assumptions are needed to determine Obtain the non-uniform stress in the film. The invention of the method and device for online measurement of film non-uniform stress applied by Feng Xue et al. It can realize the stress measurement of the film in the state of mechanical loading, and lacks the consideration of the influence of other external factors on the working state of the film; Feng Xue et al. proposed the invention of an online measurement device for the high-temperature mechanical behavior of the multilayer film matrix structure (patent application number 200810222813X) Considering the influence of the temperature field on the thin film, the stress measurement of the thin film under the action of mechanical and thermal coupling is realized. However, the actual working environment of the thin film device, especially the ferromagnetic thin film device, not only includes the force field, the thermal field, but also the iron The magnetic field environment has an important influence on the magnetism of the magnetic film. Therefore, to simulate the actual working environment of the ferromagnetic film to study the influence of various factors on the mechanical and magnetic properties of the film, it is necessary to have a film that can be subjected to force, heat, Experimental devices and methods under the action of magnetic coupling, in order to provide experimental means and basis for theoretical research and practical application of thin films.

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