Isotope Studies of Fe-18Cr-3Mo (100) Oxidation Using Raman Spectroscopy

摘要

Raman spectra have been obtained for chromia and iron-chromium spinels grown on an Fe-18Cr-3Mo (100) surface by exposure to oxygen-16, oxygen-18, and a mixture of the two isotopes, at 700 degrees C and 1.3 x 10 exp -4 Pa total pressure. Raman spectroscopy has been combined with ion bombardment to profile the isotopically tagged compounds produced during sequential oxidation in the two isotopes. We conclude that growth of spinel and chromia on this surface occurs predominantly by cation diffusion. Mixing of isotopes by diffusion within the oxide scale during these oxidations was minimal. Mixing of isotopes during ion sputtering was not an impediment to the Raman analysis. 14 references, 5 figures, 1 table. (ERA citation 10:011351)