Study On Several Influencing Factors Of EDS Analysis

The energy dispersive spectrometer(EDS)is commonly used in microscopic composition analysis.For the same analytical sample,different analysts make different results,and the difference is very considerable.Whether the selected parameters of SEM and EDS are reasonable,and whether the sample is properly handled will directly affect the accuracy of the analysis results.It is necessary to improve the accuracy of the quantitative analysis results.The choice of operating parameters,the use of techniques and the handling of the conditions of the samples themselves are worth exploring.In this paper,the factors influencing the accuracy of EDS quantitative analysis are discussed from the selection of sample preparation,scanning electron microscope and energy spectrum analyzer,and the analysis and processing of energy spectrum.Equipment used is mainly JEM-6490 SEM,EDAX-Genesis type X-ray EDS.Specific research contents and results are as follows:(1)The peak drift will affect the quantitative analysis results.Before carrying out the relevant experiment,it needs peak correction to determine the perfect peak fitness.In the point analysis mode,the small raster mode is selected.After getting the peak,chose the method of automatic peak recognition and visualization peak peeling.If it is a mistake,manually calibrate.For the choice of operating parameters,the low acceleration voltage is used to analyze the light element,and high acceleration voltage is used for heavy element.The size of the working distance can change the exit angle of the characteristic ray.Spot size controls the dead time and the rate of change,affecting the collection time.The four working parameters have an effect on the content accuracy,but the significant impact of the ability needs to be verified,and the experiment uses SPSS software to complete the orthogonal design experiment.Experiments show that the impact of these factors on the content is not significant,but the influence of the parameters is still unique for each element.(2)After excluding the influence of the working parameters on the quantitative analysis,the effect of the sample’s own conditions on the quantitative analysis is started.The sample need meets the conductivity and non-magnetic,which can avoid the charging phenomenon.The content of each element of the sample should be evenly distributed,which is determined by software uniformity test,which can eliminate the influence of uneven distribution of content.There is a carbon pollution layer on the surface of the sample.The surface of the sample always has been pollution.For the regional pollution,adjust the magnification control observation field of view respectively to test pollution and the matrix.If it is the whole area of carbon pollution,just adjust the acceleration voltage.The prolonged vacuum has no obvious effect on the carbon content.However,when the size of the sample is significantly smaller than the size of the sample stage,and the height of the sample is small,the content of the component will be affected by the sample stage.Surface-tilted samples will reduce the absorption of X-rays,resulting in increased light element content.The surface of the sample will significantly affect the X-ray generation and excitation,so the surface of the sample should be ground treatment.For a sample of the cavity wall,the experiment proved that when the distance between the failure zone and the cavity wall was not less than the cavity wall height,it is not easy to receive the occlusion of the cavity wall.