Yttrium aluminate

Aluminates. Yttrium aluminate Y3Al5012 Ce3+ (YAG) is produced by precipitation of the hydroxides with NH4OFI from a solution of the nitrates and subsequent firing at 1450 °C [5.354]. To enable a lower reaction temperature of 1300 °C, a freeze-... 

In the course of these studies key features such as olefin coordination [19,20], olefin insertion (propagation) [16,21,22], /(-hydrogen elimination [16,21,22], and /3-alkyl elimination [23] could be spectroscopically and structurally proven. In particular, yttrium aluminates have been proposed to model isoelectronic cationic homo- and heterobridged Zr/Al heterobimetallic complexes as dormant species and potential polymer chain transfer candidates [24]. Such zirconium aluminate complexes seem to be elusive [25], while the first structurally characterized titanium alumi-... 

Non-Cp ligands [119-127] those containing heteroatom compounds have been extensively explored as spectator ligands by virtue of their strong metal-heteroatom bonds and exceptional and tunable steric and electronic features required for compensating coordinative unsaturation of metal centers and for catalytic activity toward polymerization. The elegant non-Cp-ligated cationic yttrium aluminate species applied in the polymerization of 1,3-dienes was reported by Okuda. Both the yttrium aluminates (31a) and their lithium ate complexes (31b) upon activation... 

Scheme 13 Synthesis of the mono- and dicationic yttrium methyl complexes 33 and 34 from yttrium aluminate 31 or hexamethyl yttrium 32...

Numerous reports [53-62] regarding the synthesis of YAG have appeared in the literature, and in most cases the final product was either a mixture of various yttrium aluminate phases or stoichiometric YAG of undesirably large particle size. The phase inhomogeneity in the final product, through alkoxide processing, was caused by the formation of a Y-Al double alkoxide, which is a very stable compound and, hence, extremely resistant to hydrolysis [63]. For the Y and A1 isopropoxides, the two react to form a stable Y-Al double iso-propoxide according to the reaction... 

Yttrium aluminates are formed by heating Y2O3 + AI2O3 in the temperature range 900—1000... 

King, B.H., Y. Liu, R.M. Laine, and J.W. Halloran. 1993. Fabrication of yttrium aluminate fibers. Ceramic Engineering and Science... 

YAG yttrium aluminium garnet, yttrium aluminate, Y2AI5O12 ... 

Nyman M, Caruso J, HampdenSmith MJ (1997) Comparison of solid-state and spray-pyrolysis synthesis of yttrium aluminate powders. J Am Ceram Soc 80 1231-1238... 

Transparent YAG ceramics (yttrium aluminate garnet, Y3AI5O12) have excellent optical and mechanical properties. Besides flieir widespread applications in solid-state lasers, transparent YAG ceramics have also been used as envelopes in lamps [10, 11]. As expected, the corrosion resistance of YAG to rare-earth halide fills was less than that of PCA. For instance, the wall could be attacked by the rare-earth halide fills (Reis), such as Tmis, after a prolonged duration of application, due to the following reaction ... 

The samples of AIN ceramics with the best thermal conductivity are characterized by grain size of 5-10 pm. Aluminum nitride grains form continuous uniform structure without pores while the secondary phase of yttrium aluminate is... 

Figure 16.6 Thermal conductivity as a function of volume fraction of the system of the yttrium aluminate phases in AIN-Y2O3 compositions [32].

M. C. Wilding and P. F. McMillan. Liquid polymorphism in yttrium-aluminate liquids, in New Kinds of Phase Transitions Transformation in Disordered Substances, V. V. Brazhkin, S. V. Buldyrev, V. N. Ryzhov, and H. E. Stanley, eds. Kluwer Press, Dordrecht, 2002, pp. 57-73. 

Gowda G. Synthesis of yttrium aluminates by the sol-gel process. J. Mater. Sci. Lett. 1986 5 1029-1032... 

Scheme 9 Multiple C—H bond activations of a methyl group by treating a yttrium aluminate complex with a Lewis base.

Recently, partial phase diagram of yttrium aluminate and AfN was reported (40). The eutectic point of the AIN-Y4AI2O9 system was 1790°C, and the AfN-Y3Al50i2 system was as low as 1690°C, which indicated the liquid phase sintering of AIN (Fig. 21). 

WE Lee, SK Chiang, DW Readey, R Bonn, PTB Shaffer. Relation between thermal conductivity, sintering mechanism and microstructure of ALN with yttrium aluminate grain boundary phase. J Mater Sci Mater Electronics 3 93-101 (1992). 

Chromium doped yttrium aluminates perovskite type have been reported. In 2006s red perovskite ceramic pigments have been developed efficiently in different ceramic applications. [21]... 

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