Method for preparing powdered test sample for transmission electron microscope

Abstract

The invention relates to a method for preparing a powdered test sample for a transmission electron microscope. The method comprises the following steps of: cutting a crystal with a flat and neat surface from a soluble monocrystalline material according to a cleavage surface of the soluble monocrystalline material; placing an electron microscope carrying net onto the cut crystal block; ultrasonically dispersing the powdered sample to be observed by using absolute ethanol, dropping a proper amount of dispersed liquid onto the carrying net and naturally drying in the air; sputtering and depositing a layer of metal thin film by adopting a magnetron sputtering technology, and wrapping and fixing particles to be analyzed onto the carrying net by using the deposited thin film; after sputtering, shearing off a sputtered thin film along the edge of the carrying net; placing the carrying net with the fixed particles to be analyzed into an ion milling for milling until leakage; and taking down the sample and placing into the electron microscope for observation after the center of the sample is punctured. By the method, the problems that a plurality of powdered samples which have large particle size and complicated structure and are hard to smash or grind are hard to prepare, and an observation area is limited and the sample is easy to pollute can be solved; and the method is a sample preparation method with high sample preparation success rate and high suitability.

Description

(1) Technical field: [0001] The invention relates to a method for preparing a sample for a transmission electron microscope, in particular to a method for preparing a powder sample for a transmission electron microscope. (two) background technology: [0002] The transmission electron microscope is one of the important and powerful research methods to study the microscopic morphology and structure of materials, but one of the prerequisites for observing samples on the transmission electron microscope is to prepare samples suitable for electron microscope observation. The image quality and other sample information of the sample observed by the transmission electron microscope are closely related to the thickness of the sample, and the penetration ability of electrons is weak, so the sample thickness of the transmission electron microscope is generally required to be very thin, usually the thickness of the sample is below 100nm, even in high-resolution observation. The thicknes...

AI Technical Summary

Problems solved by technology

This method can still be used for particles that are easy to grind and pulverize. For some metal or alloy particles, it is difficult to thin them by grinding to meet the requirements of transmission electron microscope analysis. When looking for the edge of large particles, it can be observed. Very small, it is difficult to observe the internal morphology and structure of particles

For some composite particles or the particles themselves have a certain geometric shape, it is impossible to prepare samples suitable for observation

There is another method in the literature, which is to coat metal or alloy powder with chemical deposition or electroplating embedding method, and then reduce the thickness. However, once the particles that are easy to react with the electroplating solution are encountered, on the one hand, sample preparation becomes difficult. On the other hand, the sample is easily contaminated, which brings difficulties to the subsequent transmission electron microscope observation, and even affects the authenticity of the subsequent electron microscope analysis.