Oxides ternary systems

The GdAlgB O QiCe ", Tb " is synthesized by a soHd-state firing of the rare-earth coprecipitated oxide plus boric acid and MgCO at 900° C in a slightly reducing atmosphere. As in the case of the lanthanum phosphate phosphor, a flux is usually used. The synthesis of this phosphor is further comphcated, however, by the fact that it is a ternary system and secondary phases such as gadolinium borate form and must then react to give the final phosphor. 

Dimethylformamide is also a suitable solvent [50], it has, however, the disadvantage of being oxidized at fairly low potentials to A-acyloxy-iV-methyl formamide [51]. The influence of the composition of the ternary system water/methanol/dimethyl-formamide on the material and current yield has been systematically studied in the electrolysis of co-acetoxy or -acetamido substituted carboxylates [32]. Acetonitrile can also be used, when some water is.added [52]. The influence of various solvents on the ratio of Kolbe to non-Kolbe products is shown in Table 1 [53]. 

The salient features of surface analysis by ESCA of the oxidized ternary alloys are In general agreement with the results In the case of the binary Nl Th system. NIO, FCjO, and Th02 are the predoml-... 

Holland, H. C. (1930). The ternary system zinc oxide-zinc chloride-water. Journal of the Chemical Society, 643-8. 

Recently an analogous mechanism for cyclic chain termination has been established for quinones [47], Quinones, which can act as acceptors of alkyl radicals, do not practically retard the oxidation of hydrocarbons at concentrations of up to 5 x 10 3 mol L 1, because the alkyl radicals react very rapidly with dioxygen. However, the ternary system, /V-phenylquinonc imine (Q) + H202 + acid (HA), efficiently retards the initiated oxidation of methyl oleate and ethylbenzene [47]. This is indicated by the following results obtained for the oxidation of ethylbenzene (343 K, p02 = 98 kPa, Vi = 5.21 x 10-7 mol L 1 s 1). 

The system Ca-Zr-O is principally a ternary system. However, as long as the oxidation state of Zr and Ca are the same in all phases, the system can be redefined as a two-component system consisting of CaO and Zr02-... 

For three-component (C = 3) or ternary systems the Gibbs phase rule reads Ph + F = C + 2 = 5. In the simplest case the components of the system are three elements, but a ternary system may for example also have three oxides or fluorides as components. As a rule of thumb the number of independent components in a system can be determined by the number of elements in the system. If the oxidation state of all elements are equal in all phases, the number of components is reduced by 1. The Gibbs phase rule implies that five phases will coexist in invariant phase equilibria, four in univariant and three in divariant phase equilibria. With only a single phase present F = 4, and the equilibrium state of a ternary system can only be represented graphically by reducing the number of intensive variables. 

Lei and Zhu [63] found that adding 2.0 mol% Mn203 to llScSZ can inhibit the cubic-rhombohedral phase transformation in both oxidation and reduction atmospheres, and the codoped zirconia can reach nearly full density when sintered at temperatures as low as 850°C. The conductivity of 2Mn203-l IScSZ sintered at 900°C is 0.1 Scm-1 at 800°C. Figure 1.11 illustrates the conductivity of some zirconia-based ternary systems [32,42,57,63-67],... 

An understanding of the chemistry of these oxides and their combinations is essential to the progress of petrology. Their study should proceed from the simple to the complex, i.e., should begin with the individual oxides, then proceed to their two-component systems, then the ternary systems, and so on. Upon this fundamental basis is then erected the structure of physical properties for each system densities at all accessible temperatures, mechanical properties, fluidity, surface tension, specific and latent heats, etc. 

Temperature and pressure effects on rate constants for [Fe(phen)3] +/[Fe(phen)3] + electron transfer in water and in acetonitrile have yielded activation parameters AF was discussed in relation to possible nonadiabaticity and solvation contributions. Solvation effects on AF° for [Fe(diimine)3] " " " " half-cells, related diimine/cyanide ternary systems (diimine = phen, bipy), and also [Fe(CN)6] and Fe aq/Fe aq, have been assessed. Initial state-transition state analyses for base hydrolysis and for peroxodisulfate oxidation for [Fe(diimine)3] +, [Fe(tsb)2] ", [Fe(cage)] " " in DMSO-water mixtures suggest that base hydrolysis is generally controlled by hydroxide (de)hydration, but that in peroxodisulfate oxidation solvation changes for both reactants are significant in determining the overall reactivity pattern. ... 

Kapoor and Frohberg (1973) applied this model to the ternary system CaO-FeO-Si02. They envisaged that mixing occurred by formation of three asymmetric cells obtained by a reaction between symmetric cells of the metallic oxides and silica. For Ca0-Si02, the formation energy for the asymmetric cell is denoted Wis, where the subscripts I and S denote the combination of symmetric cells from CaO and Si02. In addition interactions between the various symmetric and asynunetric cell. were considered such that... 

Although the literature often indicates catastrophic reactions of fluorine with oxides, nitrides, carbides, silicides, borides and the like, many such species may be reacted under controlled conditions to produce oxyfluorides, nitro-fluorides such as TINF, ZrNF, HFNF, ThNF, and UNF, and other interesting ternary systems. 

However, many ternary systems incorporate a second photoactive center in addition to the [FeO ] octahedra in the present case, [NbO ] octahedra. The interaction between such multiple centers has not previously been investigated. In the present work, interband transitions are observed which appear characteristic of niobium centers, together with other transitions characteristic of the iron centers. Since these are homogeneous, singlephase materials, this result suggests that caution should be exercised when applying the conventional band model to such oxide semiconductors. 

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