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本文通过在Philips EM400T透射电镜上用一些标准成分的样品进行薄膜X射线能谱无标样成分分析实验,检验了目前国内广泛使用的美国EDAX 9100能谱仪薄膜无标样方法的分析准确度。本实验结果为:在分析Cr,Fe,Ni等相邻元素时,准确度较高,绝对误差一般在1％左右或更小;而使用同一线系分析临界激发能之比E_A/E_B≤2的近邻元素,相对误差约为5％～10％;分析非近邻元素的误差还要大些;而使用不同线系分析,相对误差可大至20％～50％。本实验认为采用高电压、尽可能使用同一线系进行分析及选取能量离得较近的X射线进行分析可以提高9100能谱仪的分析准确度。通过用TaSe_2薄膜在不同厚度与X光出射角进行的薄样品吸收实验,证明了在分析质量吸收系数之差Δμ较大的样品时,必须考虑吸收修正。用Goldstein等的薄样品吸收公式:F_(AB)=exp〔-(μ_B-μ_A)ρtcscψ/2〕可以较好地克服由薄样品吸收带来的分析误差,从而明显改善了9100能谱仪对TaSe_2的分析结果。
In this paper, the standard sample of some standard components was analyzed by Philips EM400T transmission electron microscope with no sample-like component analysis. The accuracy of the standard method of thin-film no-sample analysis of EDAX 9100 spectrometer widely used in China was tested. The experimental results show that the accuracy is high when analyzing adjacent elements such as Cr, Fe, Ni, and the absolute error is generally about 1% or less; while the critical excitation energy ratio E_A / E_B≤2 The relative error is about 5% ~ 10%; the error of analyzing non-neighbors is even larger; while using different line analysis, the relative error can be as high as 20% ~ 50%. The experiment that the use of high voltage, as far as possible using the same line for analysis and selection of energy closer to the X-ray analysis can improve the 9100 spectrometer analysis accuracy. The thin sample absorption experiments with TaSe_2 films at different thickness and X-ray exit angles demonstrate that absorption correction must be considered when analyzing samples with large Δμ differences in mass absorption coefficient. Absorbing the formula with thin sample of Goldstein et al: F_ (AB) = exp [- (μ_B-μ_A) ρtcscψ / 2] can better overcome the analytical error brought by the thin sample absorption, thus obviously improving 9100 spectrometer pair TaSe_2 analysis results.