Mossbauer spectrometry parameters

Mossbauer spectrometry is a powerful means for the elucidation of the state of iron in materials [44,138-142,145]. Figure 4.63 [44] shows the 57Fe Mossbauer spectra of the natural zeolite rocks, such as MP, C2, Cl, and C4 (see Table 4.1). In Table 4.12, the Mossbauer parameters calculated with the help of the numerical resolution of the spectra presented in Figure 4.63 are reported. That is, with the help of the recorded spectra, the accurate peak positions, integrated intensities, as well as the FWHM of each peak were calculated. This calculation was carried out by fitting the spectra with three quadrupole doublets one for site 1, another for site 2, and a last one for site 3 [44], The peaks were simulated with Gaussian functions and the fitting process for the numerical resolution of the spectra was carried was carried out with a peak separation and analysis software, developed for this purpose [44,145] based on a least square procedure [48],... 

In this work, the potential for application of Mossbauer spectrometry to corrosion studies was demonstrated for three accelerated corrosion tests in chloride environments. This technique allowed retrieving maximum information from the inherent properties of the rust layers. With VT-MS, it was possible to identify and determine the relative iron phase abundances from which three parameters could be calculated (i) a, (ii) (A + S)/(A + L + S), and (iii) PAI. Moreover, with the physical properties retrieved from the analysis of the hyperfine parameters, it was possible to discuss prospective mechanisms of formation and therefore to contribute to the understanding of the deterioration progress. These studies showed that some corrosion product is lost and/or the conversion of metallic ions into iron oxides may be incomplete, and that the relative iron phase abundances pointed out to a nonprotective and active type of rusts. More work is required on other types and chemistry (composition and abundance of alloying elements) of steels, other environmental conditions, and different exposure times. More efforts are needed to improve the fitting models for nonstoichiometric and substituted iron oxides in rust layers. 

Ste] Steyaert, S., LeBreton, J.M., Teillet, J., Kinetic Parameters of the Dissociation of Nd2Fci4B during Oxidation Determined by Mossbauer Spectrometry , J. Phys.Condens. Matter, 8(49), 10721-10736 (1996) (Morphology, Experimental, Kinetics, 22)... 

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