CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

Chapter 4
Intensity (Arbitrary units)
O1s (As polished)
Fe 2
O 3
Cr 2
O 3
Cr(OH) 3
535 534 533 532 531 530 529 528 527
Binding energy (eV)
Fig. 4.10b: XPS profile of O 1s in as polished 304L SS.
The chromium profile showed mainly two peaks, the peak around 576.8 eV is attributed to
chromium oxide (Cr 2 O 3 ), and peak at 574.3 eV is due to elemental chromium (Cr 0 ) in 304L SS,
respectively [127,128]. The oxygen profile in as polished condition revealed the presence of Fe 2 O 3
(530.1 eV), Cr 2 O 3 (530.8 eV) and Cr(OH) 3 (531.8 eV) respectively [127,128]. The presence of
iron oxide, chromium oxide, and small amount of chromium hydroxide on the polished surface is
due to naturally formed oxide, and hydroxide layer. The chromium hydroxide peak in chromium
region (Cr2p 3/2 ) was not detected as the binding energy difference between Cr(OH) 3 and Cr 2 O 3 is
very small. At concentration of 0.1 M nitric acid, Cr(OH) 3 peak was observed predominantly in
the chromium region around 577.7 eV, followed by chromium oxide peak at 576.8 eV, and
elemental chromium at 574.3 eV, respectively (Fig. 4.11a). The shift in binding energy in
chromium region was well reflected in shift in binding energy of oxygen profile also. The O1s
profile at 0.1 M nitric acid showed the presence of intense Cr(OH) 3 peak at 531.8 eV along with