CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

In addition, these peaks represent the characteristics of the different vibrational modes
of Sb-O-Sb linkages in Sb 2 O 3 . The peak maxima and line shapes are identical for all the
samples, prepared with different amount of Eu 3+ ions. Raman studies carried out over the
region 130-1000 cm -1 (Fig.50 (b)) for Sb 2 O 3 nanorods prepared both in presence and absence
of Eu 3+ ions show peaks characteristic of the orthorhombic valentinite form of Sb 2 O 3 , which
agrees well with the literature values [208-210]. As seen in Fig.50 (b), the peak position in
the Raman spectrum is similar to what has been observed in IR spectrum. The fact that the
line shape and peak position over the low frequency range (~ 100 to 1000 cm -1 ) remain
unaffected by increasing Eu 3+ concentration, clearly suggests that the Eu 3+ is not replacing
the Sb 3+ in the Sb 2 O 3 lattice. Had it been the case, the stretching and bending vibrations of the
Sb-O-Sb structural units would have affected leading to changes in the line shape and the
peak position, which is not observed in the present study. On the other hand if there is a
hydroxide formation between Sb 3+ and Eu 3+ ions, signatures corresponding to OH vibration
from this compound should be seen in the IR spectrum for the Eu 3+ containing sample.
Hence, FT-IR patterns over the region of 2500-4000 cm -1 were recoded for both the undoped
and highest Eu 3+ doped sample (10%) (Fig.51).
Absorbance (Normalised)
1.0
0.8
0.6
0.4
0.2
(b)
(a)
0.0
2500 3000 3500 4000
Wavenumber (cm -1 )
Fig.51. FT-IR patterns for the region corresponding to the OH stretching vibrations from (a)
Sb 2 O 3 nanorods (b) Sb 2 O 3 nanorods with 10 at % Eu 3+ .
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