Sesquioxides

Due to its high effective atomic number and high density, i.e., 35 and 4.56 g cm, respectively, Y2O3 could be a more effective scintillator than Yttrium [Pg.38]

6 Photographs of representative Y2O3 ceramics doped with different levels of Zr02, processed through the eombination of slip casting and vacuum sintering. Reproduced with permission from [103]. Copyright 2010, Elsevier [Pg.40]

Optical properties of Y2O3 ceramics, doped with rare-earth ions, are of special interest for some applications, such as solid-state lasers and scintillators [95]. Luminescence properties, such as upconversions, are also of special significance. For instance, REA b co-doped Y2O3 transparent ceramics (RE = Er, Ho, Pr and Tm), exhibited very efficient NIR-visible upconverters [96]. [Pg.41]

A co-precipitation method was used to synthesize LU2O3 ultrafine powder, which could be used to fabricate transparent ceramics [12]. Eu-doped LU2O3 powder was prepared by using ammonium hydroxide (NH3-H20) and ammonium hydrogen carbonate (NH4HCO3) as mixed precipitant, from solutions of nitrate salts. The precipitates were calcined at 1000 °C for 2 h, which was the optimized condition to [Pg.44]

Lead Sesquioxide. Lead sesquioxide (lead trioxide), Pb202, is an amorphous, orange-yeUow powder soluble ia cold water. It decomposes ia hot water and ia acids to lead salts plus Pb02. Lead sesquioxide can be prepared from lead dioxide by hydrothermal dissociation (43). [Pg.69]

Lead sesquioxide is used as an oxidation catalyst for carbon monoxide ia exhaust gases (44,45) (see Exhaust control), as a catalyst for the preparation of lactams (46) (see Antibiotics, P-lactams), ia the manufacture of high purity diamonds (47) (see Carbon, diamond-natural), ia fireproofing compositions for poly(ethylene terephthalate) plastics (48), ia radiation detectors for x-rays and nuclear particles (49), and ia vulcanization accelerators for neoprene mbber (50). [Pg.69]

In the sohd phase the most stable forms of Mn (ITT) are manganese sesquioxide [1317-34-6] M1I2O2, and its hydrate Mn202 and manganese... [Pg.506]

Manganese(III) Oxides. The sesquioxide, Mn202, exists in dimorphic forms. The a-Mri202 exists in nature as the mineral bixbyite. [Pg.507]

Binary Compounds. The fluorides of indium are IrF [23370-59-4] IrF [37501-24-9] the tetrameric pentafluoride (IiF ) [14568-19-5], and JIrFg [7789-75-7]. Chlorides of indium include IrCl, which exists in anhydrous [10025-83-9] a- and p-forms, and as a soluble hydrate [14996-61-3], and IrCl [10025-97-5], Other haUdes include IrBr [10049-24-8], which is insoluble, and the soluble tetrahydrate IrBr -4H20 IrBr [7789-64-2]-, and Irl [7790-41-2], Iridium forms indium dioxide [12030-49-8], a poorly characteri2ed sesquioxide, 11203 [1312-46-5]-, and the hydroxides, Ir(OH)3 [54968-01-3] and Ir(OH) [25141-14-4], Other binary iridium compounds include the sulfides, IrS [12136-40-2], F2S3 [12136-42-4], IrS2 [12030-51 -2], and IrS3 [12030-52-3], as well as various selenides and teUurides. [Pg.181]

In an alternative industrial process, resorcinol [108-46-3] is autoclaved with ammonia for 2—6 h at 200—230°C under a pressurized nitrogen atmosphere, 2.2—3.5 MPa (22—35 atm). Diammonium phosphate, ammonium molybdate, ammonium sulfite, or arsenic pentoxide maybe used as a catalyst to give yields of 60—94% with 85—90% selectivity for 3-aminophenol (67,68). A vapor-phase system operating at 320°C using a siUcon dioxide catalyst impregnated with gallium sesquioxide gives a 26—31% conversion of resorcinol with a 96—99% selectivity for 3-aminophenol (69). [Pg.311]

Forsterite. Pure forsterite is rare in nature. Most natural magnesium orthosiUcates form soHd solutions of fayaUte, Fe2Si04, and forsterite. Forsterite refractories are usually made by calcining magnesium siUcate rock such as dunite, serpentine, or oHvine with sufficient magnesia added to convert all excess siUca to forsterite and all sesquioxides to magnesia spinels. [Pg.26]

The oxide monobutyltin oxide [51590-67-1J, is a sesquioxide, C H SnO from which it is difficult to remove the last traces of water. It is an infusible, insoluble, amorphous white powder that forms when butyltin trichloride is hydrolyzed with base. The partially dehydrated material, butylstaimoic acid [2273-43-0] is slightly acidic and forms alkaH metal salts. These salts, ie, alkaH metal alkylstaimonates, form when excess alkaH is used to hydrolyze the organotin trichloride ... [Pg.74]

Alternative methods of production include reduction of HO2 with magnesium, which yields TiO only. When titanium monoxide is heated in air at 150—200°C, titanium sesquioxide, Ti202, forms, and at 250—350°C, it changes to Ti O. ... [Pg.119]

Titanium Sesc uioxide. Ti202 has the comndum stmcture. At room temperature it behaves as a semiconductor having a small (0.2 eV) band gap. At higher temperatures, however, it becomes metallic. This is associated with marked change in the mean Ti—Ti distance. As with TiO, titanium sesquioxide, Ti202, may be made by heating a stoichiometric mixture of titanium metal and titanium dioxide powders at 1600°C under vacuum in an aluminum or molybdenum capsule. [Pg.119]

Va.na.dlum(III) Oxide. Vanadium(III) oxide (vanadium sesquioxide, V2O2) is a black soHd, having the comndum (AI2O2) stmcture. It can be prepared by reduction of the pentoxide by hydrogen or carbon. Air oxidation proceeds slowly at ambient temperatures, but oxidation by chlorine at elevated temperatures to give VOCl and V20 is rapid. [Pg.391]

Antimony Trioxide. Antimony(III) oxide (antimony sesquioxide) [1309-64-4] Sb203, is dimorphic, existing in an orthorhombic modification valentinite [1317-98-2] is colorless (sp gr 5.67) and exists in a cubic form and senarmontite [12412-52-17, Sb O, is also colorless (sp gr 5.2). The cubic modification is stable at temperatures below 570°C and consists of discrete Sb O molecules. The molecule is similar to that of P40 and As O and consists of a bowed tetrahedron having antimony atoms at each corner united by oxygen atoms lying in front of the edges. This solid crystallizes in a diamond lattice with an Sb O molecule at each carbon position. [Pg.202]

Arsenic trioxide [1327-53-3] (arsenic(III) oxide, arsenic sesquioxide, arsenous oxide, white arsenic, arsenic), AS2O2, is the most important arsenic compound of commerce. The octahedral or cubic modification, arsenoHte [1303-24-8], 298 1313.9 kJ/mol (—314 kcal/mol) 214 J/(mol-K)... [Pg.333]

Cerium Oxide. The most stable oxide of cerium is cerium dioxide [1306-38-3] Ce02, also called ceria or ceric oxide. When cerium salts are calcined in air or if oxygen is present, this tetravalent Ce(IV) oxide is formed, cerium sesquioxide [1345-13-7] can be prepared in strongly reducing... [Pg.367]

Chromium Hydroxide Green. This color additive is principally hydrated chromic sesquioxide [12182-82-0], -xHpD (Cl Pigment... [Pg.451]

Chromium Oxide Green. Chromium oxide green is principally chromic sesquioxide [1308-38-9], (Cl Pigment Green 17, Cl No. [Pg.451]

Chemical Designations - Synonyms Arsenous Acid Arsenous Acid Anhydride Arsenous Oxide Arsenic Sesquioxide White Arsenic Chemical Formula AsjOj. [Pg.30]

Ln203 are all well eharaeterized. With three exeeptions they are the final produets of eombustion of the metals or ignition of the hydroxides, earbonate, nitrate, ete. The exeeptions are Ce, Pr and Tb, the most oxidized produets of whieh are the dioxides, from whieh the sesquioxides ean be obtained by eontrolled reduetion with H2. Ln203 adopt three strueture types eonventionally elassified as )... [Pg.1238]

From Pu onwards, sesquioxides become increasingly stable with structures analogous to those of Lu203 (p. 1238) Bk02 is out-of-sequence but this is presumably due to the stability of the f configuration in Bk. For each actinide the C-type M2O3 structure (metal CN = 6) is the most common but A and B types (metal CN = 7) are often also obtainable. [Pg.1268]

Melles and Backer " found, from a study of the oxidation of substituted thiophenes with perbenzoic or peracetic acid, that sulfones could be obtained from polysubstituted methyl- and phenyl-thiophenes and that the presence of electron-attracting groups, such as nitro, hindered the oxidation. Oxidation of thiophene - led to a product which was formed through a Diels-Alder reaction between the intermediate thiophene sulfoxide (211) and thiophene sulfone (212) and for which two alternative structures, (213) or (214), were suggested. Similar sesquioxides were also obtained from 2- and 3-methylthiophene and 3-phenylthiophene. The structures were not proved. Bailey and Cummins synthesized thiophene-1,1-dioxide... [Pg.106]

Ruthenium-ozyd, n. (any) ruthenium oxide, esp. the sesquioxide, ruthenium(III) oxide, -oxydul, n. ruthenium monoxide, ruthenium-(II) oxide, -saure, /. ruthenic acid, -ver-bindung, /. ruthenium compound. [Pg.374]

Sesam, m. sesame, -knorpel, m. sesamoid cartilage. -kuchen, m. sesame (oil) cake, -ol, n. sesame oil. -saat, /. sesame seed. Sesquiozyd, n. sesquioxide. [Pg.409]

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