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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.


Lattice constant and theoretical density (a) and bandgap (b) of the (Gd1−xLux)AG solid solution, as a function of the Lu content. Part (a) reproduced with permission from [17], copyright 2012 by the American Ceramic Society.
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Figure 4: Lattice constant and theoretical density (a) and bandgap (b) of the (Gd1−xLux)AG solid solution, as a function of the Lu content. Part (a) reproduced with permission from [17], copyright 2012 by the American Ceramic Society.

Mentions: A simultaneous advantage of Lu doping is that it improves the already high theoretical density of GAG (5.97 g cm−3). The (Gd0.5Lu0.5)AG solid solution, for example, reaches the high value of ∼6.44 g cm−3 (figure 4(a)), being close to that of the heavy LuAG (6.73 g cm−3). Since Gd is commercially much cheaper than Lu, the (Gd1−xLux)AG solid solutions may replace LuAG to be used as cost effective and high density scintillation materials. Assayed from UV/vis absorption, the (Gd1−xLux)AG solid solutions were found to have increasing optical bandgaps of ∼5.87, 5.97, 6.07, 6.17, 6.27, and 6.37 eV with increasing x from 0 to 0.5 (0.1 interval, figure 4(b)) [17], and the bandgap of (Gd0.5Lu0.5)AG has been close to that (∼6.40 eV) of a YAG single crystal [27]. The results may also imply that the luminescence property of a (Gd, Lu)AG based phosphor can be finely tuned by varying the Lu content and the onset of optical transmittance of a transparent (Gd, Lu)AG bulk (single crystal or transparent ceramic) would shift towards a shorter wavelength with increasing Lu incorporation.


Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd 3 Al 5 O 12 )
Lattice constant and theoretical density (a) and bandgap (b) of the (Gd1−xLux)AG solid solution, as a function of the Lu content. Part (a) 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 4: Lattice constant and theoretical density (a) and bandgap (b) of the (Gd1−xLux)AG solid solution, as a function of the Lu content. Part (a) reproduced with permission from [17], copyright 2012 by the American Ceramic Society.
Mentions: A simultaneous advantage of Lu doping is that it improves the already high theoretical density of GAG (5.97 g cm−3). The (Gd0.5Lu0.5)AG solid solution, for example, reaches the high value of ∼6.44 g cm−3 (figure 4(a)), being close to that of the heavy LuAG (6.73 g cm−3). Since Gd is commercially much cheaper than Lu, the (Gd1−xLux)AG solid solutions may replace LuAG to be used as cost effective and high density scintillation materials. Assayed from UV/vis absorption, the (Gd1−xLux)AG solid solutions were found to have increasing optical bandgaps of ∼5.87, 5.97, 6.07, 6.17, 6.27, and 6.37 eV with increasing x from 0 to 0.5 (0.1 interval, figure 4(b)) [17], and the bandgap of (Gd0.5Lu0.5)AG has been close to that (∼6.40 eV) of a YAG single crystal [27]. The results may also imply that the luminescence property of a (Gd, Lu)AG based phosphor can be finely tuned by varying the Lu content and the onset of optical transmittance of a transparent (Gd, Lu)AG bulk (single crystal or transparent ceramic) would shift towards a shorter wavelength with increasing Lu incorporation.

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.