CrLVV Auger emission and photoreduction of hexavalent Cr oxides

The CrLVV Auger emission has been used to investigate the local chemical environment of Cr(VI) in connection with the photoreduction produced by a non-monochromatic X-ray source. We compared Cr(VI) in oxides on anodized Al exposed to a chromate solution, with Cr(VI) in oxides on Al/Cr alloys polarized in a borate solution. The former were found to be much more sensitive to photoreduction than the latter. This is correlated with the intensity of the CrLVV Auger emission, attributed to a charge transfer transition in the final state of the photoemission process. © 1991.