Publication Date:
2011-12-10
Description:
To suppress the thermal decomposition and stabilize the crystal structure of Gd 3 Al 5 O 12 ( GdAG ) garnet, GdAG was doped with significantly smaller Lu 3+ to form (Gd,Lu)AG solid solutions. The precursors for ( Gd 1− x Lu x ) 3 AG ( x = 0–0.5), with a general formula of ( NH 4 ) x Ln 3 Al 5 (OH) y ( CO 3 ) z · n H 2 O ( Ln = Gd and Lu ), were synthesized via carbonate co-precipitation from the mixed solutions of aluminum, lutetium, and gadolinium nitrates using ammonium hydrogen carbonate as the precipitant. The results showed that 10 at.% of Lu 3+ ( x = 0.1) has been able to stabilize GdAG against its thermal decomposition to a mixture of GdAlO 3 ( GdAP ) and Al 2 O 3 phases at temperatures above 1300°C and that Lu 3+ doping effectively lowers the temperature for garnet crystallization. The precursors of x ≥ 0.3 convert to pure LnAG at a low temperature of ~1000°C via the intermediates of Ln 4 Al 2 O 9 ( LnAM ) and LnAP . The carbonate precursors are loosely agglomerated and the resultant LnAG powders show good dispersion and a fairly uniform particle morphology. The (Gd,Lu)AG solid solutions exhibit decreasing lattice parameters and increasing optical bandgaps along with more Lu 3+ incorporation.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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