CHEM01200604004 Shri Sanyasinaidu Boddu - Homi Bhabha ...

Figure 55 shows the representative TEM image and selected area electron diffraction
(SAED) pattern from as prepared GaPO 4 nanoparticles. The particle sizes are in the range of
25-35 nm. There are also some particle aggregates having size in the range of 40 - 65 nm.
The SAED patterns consist of dots, which are characteristic of randomly oriented single
crystalline nanoparticles. The TEM images of 2.5 at % Eu 3+ containing GaPO 4 sample is
comparable with that of the undoped GaPO 4 nanoparticles (not shown). Based on the TEM
studies it is inferred that as prepared Eu 3+ containing sample consists of crystalline GaPO 4
nanoparticles of average size of 30 nm. This suggests that Eu 3+ doping has no effect on the
particle size of GaPO 4 nanoparticles. Even though the particle size and crystallinity of the
GaPO nanoparticles containing different amounts of Eu 3+
4 ions are same, it is quite possible
that the photoluminescence properties of Eu 3+ ions can change significantly depending on the
interaction of Eu 3+ ions with the GaPO 4 nanoparticles. To understand such interactions,
detailed luminescence studies have been carried out on these samples.
Fig.55. TEM images of (a) GaPO 4 nanoparticles. The selected area electron diffraction
pattern from nanoparticles is shown in Fig.55 (b)
4.2.2. Luminescence studies: Figure 56 shows the emission spectra from GaPO 4
nanoparticles containing 2.5 and 5 at % Eu 3+ along with that from pure EuPO 4 nanoparticles
obtained after excitation at 260 nm. All the patterns are characterised by transitions from 5 D 0
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