Ternary and quaternary oxides

Various ternary and quaternary oxides of technetium can be prepared via solid state reactions (Table ll.lO.A). 

Oxidation state Composition I roperties structure Lattice constants (. 4.] References 

KuTcOs brown, hygroscopic, 500 =C dccomp. isostructural with KiRcOs [79.80] 

dark brown, hygroscopic, stable up to 650 °C isosiruciural with N ajiR.cO i — [79,80] 

)2 dark brown, stable up to 850 C isostructural with Ba3(ReOj)2 - [.32] 

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ITiis chapter covers syntheses and properties of pertcchnctic acid, pcrtcchnctic acid salts, oxotechnctatc(Vl), ternary and quaternary oxides of technetium, and the characterization of the TcOr ion. 

Besides monoxide solid solutions, a number of ternary and quaternary oxides of novel structures can be prepared by decomposing carbonate precursors containing different cations in the required proportion. Thus, one can prepare Ca Fe O, and CaFe O by heating the corresponding carbonate solid solutions in air at 1070 and 1270 K, respectively, for about 1 h. Ca Fe Oj is a defective perovskite with ordered oxide ion vacancies and has the well-known brownmillerite structure (Fig. 4.3) with... 

The ternary and quaternary oxides with CGG structure provide ample opportunities for isoelectronic (aliovalent) substitution of cations. Hence, it is not surprising that to date some sixty different compounds have been idenhfied, all of which belong to the CGG structural family. 

The XEOL of rare earths (usually Sm, Eu, Gd, Tb and Dy) present at the 100-1000 ppm level in a wide variety of simple, binary, ternary and quaternary oxide host systems have been reported by Jaworowski et al. (1968), Takashima et al. (1969), Kawaguchi et al. (1969), Saranathan et al. (1970), DeKalb et al. (1970) and D Silva et al. (1970). In addition a limited number of halides, oxyhalides, sellenides and tellurides have been shown by Low et al. (1974,J,... 

The bulk properties of simple binary oxides are pretty well understood and there are excellent reviews and books available treating the thermodynamics, the structure - and its nonstoichiometric aspects, which are particularly important for oxides - the spectroscopy, and the transport and mechanical properties [1-6]. Bulk properties of even more complicated oxides such as ternary and quaternary oxides are being intensively investigated, partly due to their importance in high-T,. superconductivity [7]. 

Lufaso MW, Woodward PM (2013) Using bond valences to model the stractures of ternary and quaternary oxides in the current S B volume... 

Using Bond Valences to Model the Structures of Ternary and Quaternary Oxides... 

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