Y2O3, synthesis

Carbothermal synthesis has been used to prepare yttrium a-sialon from mixtures of halloysite clay and Y2O3 with either Si02 or elemental Si. The reaction mechanism, particularly the role played by intermediate SiC phases, was monitored by Si NMR (Ekstrom et al. 1998). The preparation of fine-grained Ca a-sialon has also been studied by 2 Si NMR (Hewitt et al. 1994). 

A common feature of all the new ceramic superconductors is that they are cuprates, that is, they are complex copper oxides. The structure of YBCO is given in Fig. 19.3, which also shows that it is related to the perovskite structure (Fig. 4.17). Synthesis of YBCO is remarkably easy appropriate amounts of dry yttrium oxide (Y2O3), copper oxide (CuO), and barium carbonate (BaC03) are ground together into a fine, well-mixed... 

SYNTHESIS OF La, Yb CODOPED Y2O3 POWDER AND LASER CERAMICS... 

Synthesis of La, Yb Codoped Y2O3 Powder and Laser Ceramics... 

It has been reported that Y2O3 nanoparticles as-prepared by gas phase synthesis have the monoclinic stmcture of high pressure phase, which transforms into cubic Y2O3 above 873 K [7,8]. It has been elucidated from the dependence of the phase transition temperature on the state of compaction that the stability of the high pressure phase is due to the nanostructured particle size. 

FIGURE 20.14 Illustration of X-tay line broadening for a ZrO /S mol% Y2O3 powder prepared by hydrothermal synthesis. 

Ikesue A, Kamata K, Yoshida K (1996) Synthesis of transparent Nd-doped Hf02-Y2O3 ceramics using HIP. J Am Ceram Soc 79 359-364... 

Mancie L, Lojpur V, Marinkovic BA, Dramicanin MD, Milosevic Q (2013) Hydrothermal synthesis of nanostructured Y2O3 and (Yo,75Gdo,25)203 based phosphors. Opt Mater 35 1817-1823... 

Kokuoz BY, Serivalsatit K, Kokuoz B, Geiculescu O, McCormick E, Ballato J (2009) Er-doped Y2O3 nanoparticles a comparison of different synthesis methods. J Am Ceram Soc 92 2247-2253... 

Hydrothermal synthesis has also heen used to prepare rare earth oxides, (Y2O3-Gd203) Eu and Y203 (Yh /Et ), which were used for phosphors applications... 

Huang Z, Guo W, Fei BJ, Li JT, Cao YG (2013) Influence of sulphate on synthesis of Nd Y2O3 powders via coprecipitation route and fabrication of transparent ceramics. Mater Res Innovations 17 73-79... 

Luo JM, Li YX, Deng LP (2008) Synthesis of Yb Y2O3 nanocrystalline by co-precipitation method and the properties of transparent ceramics. Chin J Inorg Chem 24 260-264... 

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