Fig. 10. Rietveld analysis of the iron exsolution, based on isothermal in situ XRD experiments: temperature-dependent measurement in pure hydrogen from 673 K to 873 K and subsequent isothermal heating at 873 K (panel a) and an Ar/H2 mixture heated isothermally at 873 K (panel b). The crosses denote the Fe concentration and the red line in the upper panel the temperature. The blue line in the lower panel describes the Avrami fit applied to the data.
