standardless quantitative analysis

A system by which quantitative analysis of target elements in EDS can be conducted without using the standard specimen in each analysis. In a recent TEM, many k-factors of the Cliff-Lorimer method, which have been measured separately, are stored and tabulated in the memory of the computer on the TEM. Quantitative analysis of the elements can be performed by referring the table without measuring the standard specimen. The system or method is called "standardless quantitative analysis." In TEM, when a specimen thickness is 10 nm or less, the Cliff-Lorimer method (thin film approximation) is generally used because the absorption effect and the fluorescence excitation effect can be neglected. For example, when a specimen is composed of two elements A and B, the mass concentration ratio of element A to element B is well assumed to be proportional to the measured characteristic X-ray intensity ratio of element A to element B (proportionality factor: k). The k factor, which depends on ionization cross section, fluorescent yield, X-ray absorption by material of detector window, etc, is actually obtained from characteristic X-ray measurements of a standard specimen. It is noted that the k factor is not a constant when a specimen is thick.

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