铌酸盐材料的透射EDS定量分析及自校正方法  

EDS quantitive analysis of niobates in TEM via self-correction method

作　　者：王贤浩[1] 顾辉[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《电子显微学报》2009年第4期318-324,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金面上项目(No.50802107);国家杰出青年基金(No.50525205)

摘　　要：由于在TEM中薄试样厚度测量有难度,致使X射线能量色散谱(EDS)定量分析的相关校正难以有效进行。厚度吸收效应的自校正方法,可以不需要测量试样厚度也能进行EDS定量校正。该方法要求在谱线中包含同一元素两个不同线系,其强度比与理论值的差异就会体现出厚度效应,从而可以"间接"开展吸收的定量校正,无需通过其它途径测量试样厚度。本文通过具有固定组分的铌酸钡钠微晶验证该方法,发现铌的自校正效应可较有效地用于校正重元素钡的含量,而对于轻元素钠的校正还需考虑其它误差的作用。同样方法定量分析相同结构的铌酸锶钡织构化陶瓷,可以更为准确地测定和判定晶粒内部微区的化学组分,从而为进一步开展陶瓷材料内部微观"扩散相图"的研究工作提供必要的微分析技术基础。Because the thin foil thickness is usually unknown, correction of the absorption effect is difficult in the quantitative analysis by EDS in TEM. When there are two sets of characteristic lines from a element in the same spectrum, self-correction could be made without a measurement of thickness. The absorption due to thickness of film is manifested via the relative variation of the intensities between the two lines. The difference with ideal ratio leads to an indirect way to correct the effect of absorption without measuring the actual thickness of film. The reliability on the self-correction method was tested in the micro-crystals of tungsten bronze structured barium sodium niobate with known composition. It is found that this technique is effective for correction of content of heavy elements but it should consider other factors for the quantitative analysis of light elements. This method was also applied in the quantitative analysis of local compositions in the textured strontium barium niobate ceramics, which provide a methodological foundation for the study of the local or diffusional phase diagrams of ceramic systems.

关 键 词：X射线能量色散谱(EDS) 钨青铜型铌酸盐 定量分析 厚度吸收校正 

分 类 号：TN16[电子电信—物理电子学]