CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

All the samples show three bands centered around 345, 482 and 675 cm -1 . The peak
width increases with increase in Eu concentration and this has been assigned to the increased
distortion in the Ga 2 O 3 lattice brought about by Eu 3+ incorporation. The bands also shifted
towards lower wave numbers for the samples doped up to 0.75 at % Eu 3+ (for the samples
doped above 0.75 at %, the peak is so broad that shifting of the peak maxima could not be
clearly observed). This can be explained based on the difference in the mass of gallium and
lanthanide ions. Red shift in the peak maxima can be explained based on the heavier mass of
Eu 3+ ions compared to Ga 3+ ions, indicating the formation of Ga-O-Eu type of linkages.
Increase in broadening of the IR peaks beyond 0.75 at% is due to the conversion of
crystalline Ga 2 O 3 to an amorphous gallium oxide phase.
However, samples heated at 900°C show the crystalline nature beyond 1 at %
lanthanide ions doping (Fig.35). For the samples doped with 3 at % or more Eu 3+ , a small
peak started appearing at 2θ value of 28.4° and 32.2°. These peaks are attributed to Eu 2 O 3 .
Unit cell parameters are calculated by least square fitting of XRD patterns of 900°C heated
samples (Table 3).
*
*
5 at % Eu (11 nm)
Intensity (arb.units)
*
*
3 at % Eu (14 nm)
1 at % Eu (16 nm)
0.75 at % Eu (18 nm)
0 at% Eu (19 nm)
20 30 40 50 60 70
2θ/ o
Fig.35. XRD patterns of β-Ga 2 O 3 doped with 0, 0.75, 1, 3 and 5 at % of Eu 3+ (peak marked *
correspond to Eu 2 O 3 ). Values in brackets show average crystallite size.
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