Yttrium iron oxide

Garnets have played an important role in the development of highly sophisticated microwave devices since the development of yttrium—iron garnet, yttrium iron oxide [12063-56-8]. The iron is strongly constrained to be trivalent in order to maintain electrical neutraUty in the crystal, which is essential for low microwave losses. Garnets have lower values of saturation magneti2ation than spinels, but provide superior performance in microwave devices because they have a narrower resonance line width. 

Wu, L., Yu, J.C., Zhang, L., Wang, X., li, S. Selective self-propagating combustion synthesis of hexagonal and orthorhombic nanocrystalline yttrium iron oxide. J. Solid State Chem. 177, 3666-3674 (2004)... 

Pinkas, J., Reichlova, V., Serafimidisova, A., Moravec, Z., Zboril, R., Jandk, D., and Bezdicka, P. (2010) Sonochemical synthesis of amorphous yttrium iron oxides embedded in acetate matrix and their controlled thermal crystallization toward garnet (Y3FesOi2) and perovskite (YFeOs) nanostructures. /. Phys. Chem. C, 114,13557 13564. 

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

So-called hexagonal ferrites such as BaFe -Oi9 are ferrimagnetic and are used to construct permanent magnets. A third type of ferrimagnetic mixed oxides are the garnets, Mj FejOjj, of which the best known is yttrium iron garnet (YIG) used as a microwave filter in radar. 

Yttrium alloys have many applications. The metal doped with rare earths such as europium is used as phosphor for color television receivers. When added to iron, chromium, vanadium, niobium, and other metals it enhances resistance of these metals and their alloys to high temperature oxidation and recrystallization. It is a deoxidizer for vanadium and other nonferrous metals. Yttrium-aluminum garnets are used in lasers and in jewelery gemstones. Yttrium-iron garnets are used as transmitters and as transducers of acoustic energy. 

The oxide is used in phosphors that form red color in color television tubes. Also, it is used in gas mantles and acetylene hghts. Other uses are in yttrium-iron garnets for microwave filters in lasers, and as a stabdizer for high temperature in refractories. 

Yttrium compounds are frequently useful host materials for later Ln + ions, as mentioned in Section 5.4.4 Eu Y2O2S is the standard material for the red phosphor in virtually all colour and television cathode ray tubes, whilst Eu Y203 is used for energy-efficient fluorescent tubes. Yttrium oxide is used to stabilize zirconia (YSZ), yttrium iron garnets (YIG) are used in microwave devices, and of course YBa2Cu307 is the classic warm superconductor. Yttrium, like scandium, is naturally monoisotopic. Y has I = 1/2 though signals can be difficult to observe, valuable information can be obtained from NMR studies. 

Monophosphate tungsten bronzes with pentagonal tunnels NASICON = Sodium super ionic conductor NLO = Nonlinear Optical PLZT = Lead lanthanum zirconium titanate PZT = Lead zirconium titanate SBT = Strontium Bismuth Tantalate, SrBi2Ta209 SOFC = Solid oxide fuel cell TTB = Tetragonal tungsten bronze YAG = Yttrium iron garnet 3D = Three-dimensional TEOS = Tetraethylorthosilicate. 

The absorption due to relaxation between the possible directions of the Jahn-Teller distortions was observed initially in experiments done on the crystals of aluminum oxide (corundum), yttrium aluminum garnet, yttrium iron garnet, and lithium gallium spinel doped with 2>d ions [10,11]. 

Now we will overview some experiments that reveal the specificities of the Jahn-Teller effect in diluted crystals. First of all, we will discuss a justification of their relaxation origin. We have mentioned before that the first experiments were done on the crystals of aluminum oxide (corundum), yttrium aluminum garnet, yttrium iron garnet, and lithium gallium spinel doped with a number of 3d ions [10,11]. The main result was the discovery of attenuation maximum which was considered to be observed at cot 1 and reconstruction of the relaxation time temperature dependence. In some experiments reported later both the velocity and attenuation of ultrasound were measured as functions of the temperature. They were done on ZnSe and ZnTe crystals doped with transition metals. These crystals have the zinc-blende structure with the Jahn-Teller ion in tetrahedral coordination. The following... 

Metal oxides such as iron oxide were first reported as catalysts for the hydrogenation of carboxylic acids to the corresponding aldehydes by GAP in 1935 [4]. A typical example was the production of benzaldehyde by hydrogenation of phthalic anhydride. After this discovery the success of this system, a variety of catalysts such as y-alumina [5], vanadium oxide [6], manganese oxide [7], yttrium oxide... 

Yig, Iron yttrium oxide yttrium iron garnet. 

Diyttrium trioxide EINECS 215-233-5 YO 3-245 Yttria Yttrium oxide Yttrium oxide (Y2O3) Yttrium sesquioxide Yttrium trioxide Yttrium(3 ) oxide. Phosphors for color TV tubes, yttrium-iron garnets for microwave filters, stabilizer for high-temperature service materials. Powder d = 5.03 LDso (rat ip) = 500 mg/kg. Atomergic Chemetals New Metals Chems. Ltd Noah Chem. Rhone-Poulenc Shin-Etsu Chem,... 

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