Preparation method of transmission electron microscope observation sample of magnetic liquid in magnetic field

Abstract

The invention relates to a preparation method of a transmission electron microscope observation sample of a magnetic liquid in a magnetic field. According to the invention, a certain amount of the magnetic liquid is dispersed in a solvent, such that a mixed liquid is formed; the mixed liquid is subjected to ultrasonic oscillation for approximately 15min, such that the magnetic liquid is uniformly dispersed and is suspended in the solvent, and a transparent dispersion liquid is formed; the dispersion liquid is placed in a transverse magnetic field and a longitudinal magnetic field; according to the testing requirements of the transverse magnetic field and the longitudinal magnetic field, a copper screen position is determined with the assistance of coordinate lines; the copper screen is immersed in the dispersion liquid, and is stood for 1min; the copper screen is drawn back, and is dried on a sealing membrane. Because of the high adsorption capacity of the magnetic particles, a single-layer magnetic particle chain structure is picked up by the copper screen, such that the transmission electron microscope observation sample of the magnetic liquid in the transverse magnetic field or the longitudinal magnetic field is prepared. The sample is delivered to a transmission electron microscope observation room, and the distribution state and arrangement condition of the magnetic particles in the transverse magnetic field or the longitudinal magnetic field can be observed.

Description

technical field [0001] The invention belongs to the field of electron microscope preparation technology and material analysis, and provides a method for preparing a transmission electron microscope test sample of a magnetic liquid in a magnetic field, which is suitable for observing various magnetic liquids with a magnetic particle diameter of about 10nm in the magnetic field. Background technique [0002] Magnetic liquid is a superparamagnetic magnetic material, a solid-liquid two-phase colloidal solution formed by uniformly dispersing surfactant-coated single-domain magnetic particles with a diameter of about 10nm in a carrier liquid. Different from traditional magnetic materials, magnetic liquids have both the magnetism of solids and the fluidity of liquids. They often exhibit unique physical and chemical properties and are widely used in the fields of mineral processing, sealing and lubrication. According to literature records, 1 cm 3 The ferrofluid contains 10 18 Magn...

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Problems solved by technology

Although this method is feasible, the preparation process is cumbersome, and the magnetic particles are exposed to the air for a long time, which is easy to be oxidized, and the overlapping of the magnetic particles is serious, which cannot truly reflect the surface morphology of the magnetic particles and the distribution of the magnetic particles in the magnetic field. , as attached figure 2 shown

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