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Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd 3 Al 5 O 12 )

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ABSTRACT

This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd3+ to the activator. Ce3+ doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out.

No MeSH data available.


The effects of Lu content (x value) on phase evolution of (Gd1−xLux)AG solid solution. Parts (a) and (b) are for calcination temperatures of 1000 and 1500 °C, respectively. Reproduced with permission from [17], copyright 2012 by the American Ceramic Society.
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Figure 3: The effects of Lu content (x value) on phase evolution of (Gd1−xLux)AG solid solution. Parts (a) and (b) are for calcination temperatures of 1000 and 1500 °C, respectively. Reproduced with permission from [17], copyright 2012 by the American Ceramic Society.

Mentions: Lu3+ (0.0977 nm for CN = 8) is the tiniest Ln3+ ion and would thus be the most effective to stabilize GAG via replacing the Gd3+ site to form a (Gd1−xLux)AG solid solution. With coprecipitated carbonate precursors, Li et al [17] thoroughly studied the effects of Lu content on phase evolution and also properties of the resultant (Gd1−xLux)AG (x = 0–0.5). It was shown that the garnet phase generally crystallizes via LnAM and LnAP intermediates, as is commonly observed for YAG, but the crystallization temperature substantially decreases towards a higher Lu content. With x = 0.3–0.5, phase-pure garnet can even be crystallized at a temperature as low as 1000 °C (figure 3(a)), revealing the significant effectiveness of Lu3+ doping. Again, only a phase mixture of LnAG, LnAP and amorphous Al2O3 was produced in the absence of Lu3+ (figure 3(b)).


Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd 3 Al 5 O 12 )
The effects of Lu content (x value) on phase evolution of (Gd1−xLux)AG solid solution. Parts (a) and (b) are for calcination temperatures of 1000 and 1500 °C, respectively. Reproduced with permission from [17], copyright 2012 by the American Ceramic Society.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036492&req=5

Figure 3: The effects of Lu content (x value) on phase evolution of (Gd1−xLux)AG solid solution. Parts (a) and (b) are for calcination temperatures of 1000 and 1500 °C, respectively. Reproduced with permission from [17], copyright 2012 by the American Ceramic Society.
Mentions: Lu3+ (0.0977 nm for CN = 8) is the tiniest Ln3+ ion and would thus be the most effective to stabilize GAG via replacing the Gd3+ site to form a (Gd1−xLux)AG solid solution. With coprecipitated carbonate precursors, Li et al [17] thoroughly studied the effects of Lu content on phase evolution and also properties of the resultant (Gd1−xLux)AG (x = 0–0.5). It was shown that the garnet phase generally crystallizes via LnAM and LnAP intermediates, as is commonly observed for YAG, but the crystallization temperature substantially decreases towards a higher Lu content. With x = 0.3–0.5, phase-pure garnet can even be crystallized at a temperature as low as 1000 °C (figure 3(a)), revealing the significant effectiveness of Lu3+ doping. Again, only a phase mixture of LnAG, LnAP and amorphous Al2O3 was produced in the absence of Lu3+ (figure 3(b)).

View Article: PubMed Central - PubMed

ABSTRACT

This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd3+ to the activator. Ce3+ doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out.

No MeSH data available.