Mossbauer Spectrometry of Model Binary Fe100-xCrx (1 ≤ x ≤ 50) Alloys

Herein, several ways to evaluate Mossbauer spectra of model binary Fe100-xCrx alloys with chromium content varying in the range from 1 to 50 at% (x = 0.94, 2.2, 4.9, 10.4, 15.4, 22.1, and 52.9) are discussed. For low chromium concentrations (up to 15 at%), the method of binomial distribution of individual sextets is suitable. Depending upon the Cr content, the number of sextets used can be, however, as high as 20. The specific number of sextets is determined according to probabilities of individual atomic sites calculated from binomial distribution. Mossbauer spectra of samples with Cr concentrations higher than 20 at% are evaluated by distributions of hyperfine magnetic fields. The composition of model alloys is verified using X-ray fluorescence. Their surface is analyzed by two different surface-sensitive methods: scanning electron microscopy and atomic force microscopy. The main technique used to analyze the materials' subsurface layers is conversion electron Mossbauer spectroscopy. The applied fitting models and results are useful in studies of the microstructure of real types of construction and stainless steels.