Yttrium -oxide

Akinc and Celikkaya [169], on the other hand, synthesized yttrium oxide where the stock solution of yttrium (0.25 M) was prepared in a similar way this solution was dispersed in toluene as the continuous phase, containing a dissolved mixture of Span 60 (Sorbitan monostearate) and Tween 80 (the most satisfactory volume ratio was 2 1) as emulsifier. Triethanolamine was used as the precipitating agent, while methanol was used for breaking the emulsion. A standard emulsion formulation had 150 ml of the water phase dispersed in 430 ml of the oil phase, with 10 g of Span 60 and 8 ml of Tween 80. The spherical particles of Y2O3 obtained by calcination at 700 C had a size range of 0.2-2 pm, peaking at around 0.6 pm. In another work, Celikkaya and Akinc [192] destabilized the system after precipitation by addition into acetone. 

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This also illustrates the use of different wavelengths of light to obtain much more infomration on the nature of the film. Here A and T are plotted versus the wavelength of light ( ) and the line drawn tln-ough these data represents a fit calculated for the various fihns of yttrium oxide deposited on silica as shown at tire bottom of the figure [40],... 

Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use. It is widely used in making YVOr europium, and Y2O3 europium phosphors to give the red color in color television tubes. Many hundreds of thousands of pounds are now used in this application. 

Yttrium oxide also is used to produce yttrium-iron-garnets, which are very effective microwave filters. 

For elimination of intramolecular energy losses, we have synthesized ligands with high hydrophobisity - perfluoro-P-diketones R -CO-CH -CO-R, (R = CgF j or CgF R = phenyl or a-thienyl), that without second ligand eliminate completely water molecules from the inner coordination sphere. These ligands we have used in analysis at determination of Sm, Eu, Nd, Yb microamounts in high-purity lanthanide and yttrium oxides. 

Solid oxide fuel cells consist of solid electrolytes held between metallic or oxide elecU odes. The most successful fuel cell utilizing an oxide electrolyte to date employs Zr02 containing a few mole per cent of yttrium oxide, which operates in tire temperature range 1100-1300 K. Other electrolytes based... 

In 1794 the Finnish chemist J. Gadolin, while examining a mineral that had recently been discovered in a quarry at Ytterby, near Stockholm, isolated what he thought was a new oxide (or earth ) which A. G. Ekeberg in 1797 named yttria. In fact it was a mixture of a number of metal oxides from which yttrium oxide was separated by C. G. Mosander in 1843. This is actually part of the fascinating story of the rare earths to which we shall return in Chapter 30. The first sample of yttrium metal, albeit very impure, was obtained by F. Wohler in 1828 by the reduction of the trichloride by potassium. 

Conceptually elegant, the SOFC nonetheless contains inherently expensive materials, such as an electrolyte made from zirconium dioxide stabilized with yttrium oxide, a strontium-doped lanthanum man-gaiiite cathode, and a nickel-doped stabilized zirconia anode. Moreover, no low-cost fabrication methods have yet been devised. 

Goldschmidt has classed also with the ionic crystals the C-modification of the sesqui-oxides, cubic crystals with 16 M2O3 in the unit of structure. The inter-atomic distances reported by him are 2.16-2.20 A. for scandium oxide and 2.34-2.38 A. for yttrium oxide, in good agreement with the radius sums 2.21 A. for Sc+3-0= and 2.33 A. for Y+3-0". 

Samples with different loadings of rare earth and yttrium oxides on MS25 Si-Al were prepared and characterized. Figure 1 shows the x-ray diffraction spectra of a sample of 25% Nd203/Si-Al compared with the unmodified Si-Al. 

Rare Earths are produced primarily from three ores, monazite, xenotime, and bastnasite. Monazite is a phosphate mineral of essentially the cerium subgroup metals and thorium -(light rare Earths, Th) P04. The composition of monazite is reasonably constant throughout the world, with almost 50% of its rare Earth content as cerium and most of the remaining 50% as the other members of the cerium subgroup. Xenotime, like monazite, is a rare Earth orthophosphate but contains up to 63% yttrium oxide and also a markedly higher propor-... 

Barium acetate, Yttrium oxide See Barium acetate Copper(II) oxide, etc. 

Siriwardane, R.V., J.A. Poston, E.P Fisher, T.H. Lee, S.E. Dorris, and U. Balachandran, Characterization of ceramic-metal composite hydrogen separation membranes consisting of barium oxide, cerium oxide, yttrium oxide, and palladium, Appl. Surf. Sci., 217, 43-49, 2003. 

Yttrium—gallium compounds, 12 353—355 Yttrium oxide, 14 650 in SiC-ceramic fabrication, 22 535 Yttrium trifluoride, 8 340 Y-TZPb... 

PPG Industries has developed a substitute for lead in a coating process used widely in the auto industry. The replacement is yttrium that, though much less studied than lead, is considered orders of magnitude lower in hazard. In addition it was discovered that as yttrium is used in the process it is converted to yttrium oxide that is appears to be non-toxic by ingestion, in stark contrast to lead. As PPG customers implement yttrium overthe next several years, it is projected that the use of approximately one million pounds (some 454 tonnes) of lead will be avoided. 

Because yttrium has just one oxidation state (+3), it joins with oxygen to form yttrium oxide (2Y + 30 —> Y O ), which is used to produce the red colors in TV and computer screens. 

Compounds Yttrium chloride yttrium nitrate yttrium oxide yttrium phosphate... 

No effects in humans have been reported. Intratracheal administration of 50 mg of yttrium oxide in rats caused granulomatous nodules to develop in the lungs by 8 months. Nodules in the peribronchial tissue compressed and deformed several bronchi the surrounding lung areas were emphysematous, the interalveolar walls were thin and sclerotic, and the alveolar cavities dilated. Intraperitoneal injection... 

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