Yttrium yttria

Ytterby, a village in Sweden near Vauxholm) Yttria, which is an earth containing yttrium, was discovered by Gadolin in 1794. Ytterby is the site of a quarry which yielded many unusual minerals containing rare earths and other elements. This small town, near Stockholm, bears the honor of giving names to erbium, terbium, and ytterbium as well as yttrium. 

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. 

Ytter-erde, /. yttria (as class name) yttrium earth, -flussspat, m. yttrocerite, ytterhaltig, a. contammg yttrium, yttriferous, yttric. 

Yttria-stabilized zirconia by codeposition of tetramethyl heptadione of zirconium and yttrium, Zr(C Hi902)3 and Y(CnHi902)3 at 735°C. 

Attempts to deposit yttria-stabilized zirconia by combining Reaction (1) and a similar hydrolysis of YCI3 as source of yttrium at 700-1000°C were inconclusive, Codeposition from the chlorides... 

MOCVD of Zirconia. Yttria-stabilized zirconia is also deposited by MOCVD.Deposition can be accomplished by the codecomposition of the tetramethyl heptadiones of zirconium and yttrium, Zr(CjjHj902)3 and Y(CjjHj902)3, at 735°C. Deposition is also achieved by the decomposition of the trifluoro-acetylacetonates in a helium atmosphere above 300°C.P 1 Other potential MOCVD precursors are bis(cyclopentadienyl)zirconium dichloride, (C5H5)2ZrCl2, and zirconium (IV) trifluoroacetylacetonate,... 

Another application is in the oxidation of vapour mixtures in a chemical vapour transport reaction, the attempt being to coat materials with a thin layer of solid electrolyte. For example, a gas phase mixture consisting of the iodides of zirconium and yttrium is oxidized to form a thin layer of yttria-stabilized zirconia on the surface of an electrode such as one of the lanthanum-strontium doped transition metal perovskites Lai Sr MO --, which can transmit oxygen as ions and electrons from an isolated volume of oxygen gas. 

Y-section rayon, 11 262, 263 Ytterbium (Yb), 14 631t, 635t electronic configuration, l 474t Yttria, 5 583, 14 630 Yttria-stabilized zirconia (YSZ), 26 637 Yttric rare earths (RE), 14 631 Yttrium(III)... 

The element was discovered in 1794 by the Swedish chemist Gadolin. He named it after the small town Ytterby in Sweden where the mineral containing yttria was found. Mosander in 1843 determined that the yttria consisted of three oxides yttria, erbia, and terbia. Yttrium occurs in all rare earths. It is recovered commercially from monazite sand, which contains about 3% yttrium. It also is found in bastnasite in smaller amounts of about 0.2%. Abundance of yttrium in earth s crust is estimated to be 33 mg/kg. The metal has been detected in moon rocks. 

Using the same procedure, spherical nanosize particles of hematite were coated with yttrium basic carbonate and showed that various surface thermodynamic properties of these systems were essentially those of yttria (37). 

Samarskite occurs in the Ural Mountains, Mitchell County (North Carolina, U.S.A.), Canada, and India. The tantalum content is often small, sometimes nil, and the rare earth oxides, chiefly yttria and ceria, are usually present in considerable number and proportions. The ore is radioactive and contains helium. It forms black, orthorhombic crystals. The density varies from 4-2 to G-2.5 It has been suggested that the niobium and tantalum are disintegration products of compounds of yttrium and cerium with the two higher homologues of manganese,4 masurium, and rhenium. 

An entirely different selectivity principle known as phase equilibrium comes into play in high-temperature ionic conductors. Many important gases dissolve in ionic solids at elevated temperatures. However, the solubility is rather sharply defined for the gas and the solid by the lattice parameters and the size of the gas molecule. The best example is the solubility of oxygen in zirconium dioxide. When Z1O2 is doped with yttrium ions, it exhibits a high mobility for the O anion. The solubility and anion mobility then become the basis for several electrochemical gas sensors, using yttria-stabilized zirconia (YSZ). 

Gadolin is recognized for having discovered the element yttrium in 1794. He had been studying a black mineral that had been found by Karl Axel Arrhenius (1757-1824) in Ytterby, Sweden. The mineral was eventually named gadolinite. Working with the mineral, Gadolin was able to isolate an oxide substance (apparently the oxide of a new element) that was later named yttria. The existence of the new element, yttrium, was eventually confirmed. 

Y NMR has also been reported extensively from yttrium sialon ceramics. Yttria is an important sintering aid for densifying silicon nitride. The properties of the sialon produced are determined by the nature of the grain boundary phase, which is usually a crystalline or glassy yttrium sialon. The often disordered nature of such phases can mean that broader 89Y resonances are... 

Yttria, Y203, can be prepared from a reaction of yttrium nitrate and urea (Shea et al., 1996) ... 

The use of metal nitrates provides a particularly convenient method for doping a host oxide with luminescent ions. Along with the yttrium nitrate, a luminescent rare earth ion such as Eu3+, can be added as a nitrate salt. In addition to yttria, alumina can also be prepared from aluminum nitrate and hydrazine (Ozuna et al., 2004) ... 

There is an obvious overlap among various applications categories. An example of the overlap is alumina which is both a structural refractory ceramic as well as a catalyst support. The additives modify the interconversion of various AI2O3 phases and the high surface area of y-Al203 is maintained by the added 3 wt% ceria or lanthana. Additives like yttria stabilize zirconia with respect to inertness and mechanical stability. Addition of yttrium or lanthanide to Fe-Cr-Al alloys reduces the spallation of oxide film. 

Oxygen anions travel from the source side through the solid electrolyte to the sink side (anode) under the combination of the influence of an applied dc electric field and an oxygen chemical potential gradient. At the sink side (the anode of the SOFC), the oxygen anions react electrochemically with both zirconium and yttrium reactants from the sink vapor phase to form the desired product, yttria doped zirconia, and release electrons to the metallic anode. Electrons travel through the external electrical circuit back to the source side for further cathodic reaction. 

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