Quantitative analysis of thin specimens in the TEM using a φρ(ζ)-model

X-ray microanalysis using Transmission Electron Microscopy (TEM) offers the possibility to perform quantitative analysis with high spatial resolution. Unfortunately, the accuracy is limited and the preparation of the very thin specimens and thin film standards, needed for the analysis and calibration, is rather difficult. To calculate the composition from the measured X-ray intensities, a peak-ratio method is usually applied, based on the well-known thin film approach proposed by Cliff and Lorimer in 1972.In the present paper we propose an entirely different approach, in which the compisition is calculated using a full matrix correction method based a a ö(ñz)procedure. Nowadays, such correction models are commonly used in bulk EPMA measurements up to 40kV. The validity of the model under TEM condiditons was checked by performing bulk analyses on AlNi and AlTi samples and thin film analyses on a AlNi TEM specimen. Using this method, both thin and thick specimens as well as light elements can be analysed, without having to prepare thin film standards. No major changes to the TEM set-up or simplifications to the model are needed, only an accurate beam current meter is required. As an example of the possibilities, a linescan analysis was made on a GaAs specimen with GaAs/Ti interface, using only bulk standards. Finally, a comparison of our analysis method with other available thin film methods is included in this article.