Quantitative analysis of mixed (Mo,W) carbides by means of least-squares minimization performed on auger spectra simulations
✍ Scribed by Silberberg, E.; Reniers, F.; Buess-Herman, C.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 217 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0142-2421
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✦ Synopsis
Surface analysis was performed by Auger spectroscopy on mixed (Mo,W) carbides that were synthesized with a 50 : 50 molar ratio of both metals. Because of the molybdenum and tungsten Auger peak overlap in the energy window between 100 and 230 eV, a linear combination of appropriately chosen standard spectra was requested in order to determine their composition quantitatively. Therefore, molybdenum, tungsten and mixed (Mo,W) carbides were prepared and characterized by electron and x-ray di †ractions. The di †raction techniques allowed the determination of the carbide phases corresponding to speciÐc metal/carbon stoichiometries. The Auger spectra of mixed (Mo,W) carbides were simulated by weighted sums of the Auger spectra of a-WC and MoC. A least-squares method was applied on the simulated Auger spectra, in the whole energy window, in order to determine the best simulation revealing the true composition of the mixed (Mo,W) carbides. This technique requires the homogeneity of the sample over a larger depth than the inelastic mean free path of the Auger electrons. Moreover, it allowed the determination of di †erent compositions of mixed (Mo,W) carbides resulting from di †erent preparation routes.