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Green-Emitting Gd 3 Ga 5 O 12 : Tb 3+ Nanoparticles Phosphor: Synthesis, Structure, and Luminescence

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ABSTRACT

Nano- and microceramics of Gd3Ga5O12 garnet doped with 1 mol % Tb3+ ions were synthesized via co-precipitation and high-temperature solid-state reaction methods. X-ray diffraction measurements confirmed the formation of the garnet structure with Ia3d space group in all investigated samples. Atomic force microscopy surface images and grain-size distribution diagrams of Gd3Ga5O12: 1 mol % Tb3+ nanoceramics with 300 and 400 g/mol of polyethylene glycol (PEG) were obtained. The relationship between the content of polyethylene glycol and the particle size of Gd3Ga5O12: Tb3+ phosphors was revealed. An intense broad band (λm = 266 nm) related to spin-allowed 4f8-4f75d1 transitions of Tb3+ ions was found in photoluminescence excitation spectra of Gd3Ga5O12: Tb3+ nanocrystalline ceramics with PEG-300 and PEG-400 at 300 K. The broad excitation band caused by spin-forbidden (λm = 295 nm) 4f-5d transitions in Tb3+ ions was additionally observed in the photoluminescence excitation spectra of Gd3Ga5O12: Tb3+ microceramics. Emission of Tb3+ ions under X-ray and UV excitations is presented by two groups of sharp lines which correspond to 5D3 and 5D4 → 7Fj transitions of Tb3+ ions with the most intense line at 546 nm (5D4 → 7F5). It was established that the increasing of PEG content leads to the decreasing of the X-ray and photoluminescence emission intensities.

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X-ray luminescence of 1 mol % Tb3+-doped Gd3Ga5O12 micro- (red) and nanoceramics (green—Nano PEG-400, blue—Nano PEG-300) at room temperature
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Fig6: X-ray luminescence of 1 mol % Tb3+-doped Gd3Ga5O12 micro- (red) and nanoceramics (green—Nano PEG-400, blue—Nano PEG-300) at room temperature

Mentions: X-ray luminescence spectra of Tb3+-doped Gd3Ga5O12 nano- and microceramics are shown in Fig. 6. Characteristic strong lines assigned to the 5D3 → 7Fj and 5D4 → 7Fj (j = 6, 5, 4, 3) transitions of the Tb3+ ions are observed. These emission lines can be separated in two groups. The blue emission below 480 nm is related with 5D3 → 7Fj transitions, while the green emission above 480 nm is from 5D4 → 7Fj transitions. The intensity of the blue emission (Fig. 6) is significantly weaker than the green emission for all ceramics. As it was shown in [9], the spectral energy distribution of Tb3+ emission is strongly dependent on the Tb concentration in the case of Y3-xAl5O12:Tbx powders. The blue emission (5D3 → 7Fj) dominates for very low Tb concentrations (<0.1%) and completely disappears for concentrations above ~2% [9]. Therefore, when in the investigated micro- and nano-sized samples, the concentration of Tb3+ is 1 mol %, the cross-relaxation begins, and the rate for the cross-relaxation depends on the concentration of Tb3+ ions [1, 10].Fig. 6


Green-Emitting Gd 3 Ga 5 O 12 : Tb 3+ Nanoparticles Phosphor: Synthesis, Structure, and Luminescence
X-ray luminescence of 1 mol % Tb3+-doped Gd3Ga5O12 micro- (red) and nanoceramics (green—Nano PEG-400, blue—Nano PEG-300) at room temperature
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Related In: Results  -  Collection

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Fig6: X-ray luminescence of 1 mol % Tb3+-doped Gd3Ga5O12 micro- (red) and nanoceramics (green—Nano PEG-400, blue—Nano PEG-300) at room temperature
Mentions: X-ray luminescence spectra of Tb3+-doped Gd3Ga5O12 nano- and microceramics are shown in Fig. 6. Characteristic strong lines assigned to the 5D3 → 7Fj and 5D4 → 7Fj (j = 6, 5, 4, 3) transitions of the Tb3+ ions are observed. These emission lines can be separated in two groups. The blue emission below 480 nm is related with 5D3 → 7Fj transitions, while the green emission above 480 nm is from 5D4 → 7Fj transitions. The intensity of the blue emission (Fig. 6) is significantly weaker than the green emission for all ceramics. As it was shown in [9], the spectral energy distribution of Tb3+ emission is strongly dependent on the Tb concentration in the case of Y3-xAl5O12:Tbx powders. The blue emission (5D3 → 7Fj) dominates for very low Tb concentrations (<0.1%) and completely disappears for concentrations above ~2% [9]. Therefore, when in the investigated micro- and nano-sized samples, the concentration of Tb3+ is 1 mol %, the cross-relaxation begins, and the rate for the cross-relaxation depends on the concentration of Tb3+ ions [1, 10].Fig. 6

View Article: PubMed Central - PubMed

ABSTRACT

Nano- and microceramics of Gd3Ga5O12 garnet doped with 1&nbsp;mol&nbsp;% Tb3+ ions were synthesized via co-precipitation and high-temperature solid-state reaction methods. X-ray diffraction measurements confirmed the formation of the garnet structure with Ia3d space group in all investigated samples. Atomic force microscopy surface images and grain-size distribution diagrams of Gd3Ga5O12: 1&nbsp;mol&nbsp;% Tb3+ nanoceramics with 300 and 400&nbsp;g/mol of polyethylene glycol (PEG) were obtained. The relationship between the content of polyethylene glycol and the particle size of Gd3Ga5O12: Tb3+ phosphors was revealed. An intense broad band (&lambda;m&thinsp;=&thinsp;266&nbsp;nm) related to spin-allowed 4f8-4f75d1 transitions of Tb3+ ions was found in photoluminescence excitation spectra of Gd3Ga5O12: Tb3+ nanocrystalline ceramics with PEG-300 and PEG-400 at 300&nbsp;K. The broad excitation band caused by spin-forbidden (&lambda;m&thinsp;=&thinsp;295&nbsp;nm) 4f-5d transitions in Tb3+ ions was additionally observed in the photoluminescence excitation spectra of Gd3Ga5O12: Tb3+ microceramics. Emission of Tb3+ ions under X-ray and UV excitations is presented by two groups of sharp lines which correspond to 5D3 and 5D4&thinsp;&rarr;&thinsp;7Fj transitions of Tb3+ ions with the most intense line at 546&nbsp;nm (5D4&thinsp;&rarr;&thinsp;7F5). It was established that the increasing of PEG content leads to the decreasing of the X-ray and photoluminescence emission intensities.

No MeSH data available.