Comfortable sample double spray electrolytically thinning instrument for transmission electronic microscopy

Abstract

An electrolytic thickness reducer is composed of DC power, electrolytic device of magnetic agitation and double spray and illumination device. It is featured as using 0-36 V span for DC power, placing a p-m pole in double spray component set in outer organic box with electrolyte, using stainless steel sheet as negative pole, placing positive sample in between two nozzles, having electron microscopic sample conducted with phi 0.3 mm Pt wire and stainless steel bar and having parallel light conducted out by all reflecting cable.

Description

technical field [0001] The invention belongs to the technical field of sample preparation equipment manufacturing, and in particular provides a convenient and practical double-spray electrolytic thinning instrument for transmission electron microscope samples, which is a new complete set of equipment suitable for manufacturing transmission electron microscope experiment materials. Background technique: [0002] At present, in most colleges and research institutes in my country, most of the electrolytic double-spray instruments used to make TEM samples are domestically produced, and the main one is the MTP-1 electrolytic double-spray sample preparation instrument of Shanghai Jiaotong University, such as figure 1 As shown, there are the following disadvantages: (1) Compared with foreign countries, the electrolytic polishing current range is narrower (0-15mA range), and the corresponding parameters of foreign equipment are generally an order of magnitude higher (0-400mA range). ...

AI Technical Summary

Problems solved by technology

[0002] At present, in most colleges and research institutes in my country, most of the electrolytic double-spray instruments used to make TEM samples are domestically produced, and the main one is the MTP-1 electrolytic double-spray sample preparation instrument of Shanghai Jiaotong University, such as figure 1 As shown, there are the following disadvantages: (1) Compared with foreign countries, the electrolytic polishing current range is narrower (0-15mA range), and the corresponding parameters of foreign equipment are generally an order of magnitude higher (0-400mA range). When the double-jet instrument is used to make thin film samples for transmission electron microscopy, the range of electrolytic current at room temperature is strictly limited. Domestic colleges and research institutes mainly reduce the temperature of the electrolyte (-15°C to -5°C) to achieve The purpose of reducing the electrolysis current of the electrolyte is to obtain a satisfactory metal thin film sample, but the experimental temperature control process is cumbersome, and the low temperature condition is very unfavorable to the service life of the electrolytic double jet instrument, especially the damage to the instrument caused by liquid nitrogen quenching , mixing liquid nitrogen into the electrolyte has a significant cooling effect, but changes the effective concentration of the electrolyte; (2) Due to the rapid flow of the electrolyte, it is difficult for the double-jet electrolytic polishing to appear the limiting current plateau area pointed out by the theory, and its I-V curve is almost in a straight line, such as figure 2 As shown, the shape of the polished sample is different in each area of ​​the curve: corrosion occurs in the low-voltage area; the voltage is too high and the edge of the sample is perforated, and the film quality is not good; only the thinning at B is the best, and a large flat film can be obtained. But it is not easy to explore; (3) The material of the sample itself and its physical state, the composition of the electrolyte, the relationship between temperature and voltage and current values, the size of the instrument nozzle, the distance between electrodes, the shape of the sample holder and the flow rate of the electrolyte are all important factors for sample preparation. There are different degrees of influence, and the product design is difficult to meet or take into account. According to user reports, the nozzle of the instrument made of plastic is aging and deformed after being used for a long time, and the liquid columns ejected from the two nozzles cannot be accurately docked; (4) The alarm sensitivity of the photosensitive device is poor, The formation of micropores by visual inspection does not necessarily indicate the formation of sufficiently large or sufficiently thin areas; (5) Once the optimal polishing conditions are determined and the polished sample is pierced, it is recommended to clean the sample immediately without removing the voltage, but the existing models The design of the sample holder of the sample preparation device makes it too late for the sample to be cleaned quickly, and the thin area on the edge of the small hole is corroded

[0003] Li Qiaoling, Ye Yun, North China Institute of Technology. "Preparation of metal permeated thin film samples from a mixture of perchloric acid and glacial acetic acid at room temperature", Communication of Analytical and Testing Instruments, 1995, 6(2): 93-94, using 0.46mol / L HClO 4 -16.7mol / L HAc electropolishing solution was used to conduct experiments, and the electropolishing parameters for preparing metallized film samples at room temperature (5~15°C) were determined, which were prepared by Bollmann method (edited by Chen Shipu, Wang Yongrui. Electron Microanalysis of Metals. Beijing : Mechanical Industry Press, 1982: 102) Electron microscope thin film samples provide a method for selecting electrolytic parameters, which obviously does not have universal applicability to materials; and textbooks think that preparing thin film samples for transmission electron microscopy generally uses 12mol / L HClO 4 The electrolytic polishing solution (Li Shutang. Metal X-ray and electron microscopic analysis. Beijing: Metallurgical Industry Press, 1980: 224) composed of absolute ethanol with a volume fraction of 90% is carried out at -10~-20°C , many documents give which kind of material should use which kind of electrolyte and its applicable temperature (Wu Xingfang, Liu Delu. Practical Methods of Electron Microanalysis. Beijing: Metallurgical Industry Press, 1998: 12-13; Li Qiaoling, Ye Yun .Zhao Xingguo.Research on the development and parameter selection of room temperature electrolytic polishing fluid. Shanxi Machinery, 1997, 4(97): 12-16; Ma Shubo. Physical testing of sample preparation technology for transmission electron microscope, 1995, 1: 42-45), experimenter It is not easy to determine the parameters of electropolishing

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