Initial oxidation of Fe-Al and Fe-Cr-Al alloys: Cr as an alumina booster
  The boosting effect of Cr on the growth of the protective alumina scale on Fe-Al alloys is investigated by x-ray photoelectron spectroscopy. Using low oxygen pressure the surface chemistry of the alloys is monitored starting from the first moments of oxidation. Chromium effect on the Fe-Al surface-bulk exchange is clearly detected by analyzing the measured surface concentrations within the atomic concentration models. Previous ab initio calculations agree well with the present experiments. 
Markku Heinonen, Kalevi Kokko, Marko Punkkinen, Eero Nurmi, Janos   Koll\'ar, Levente Vitos
cond-mat.mtrl-sci