Perovskites synthetic

Numerous investigators have attempted to control the precursor structure and related solution chemistry effects with varying degrees of success, to influence subsequent processing behavior, such as crystallization tempera-ture.40-42,78,109 110 Particular attention has been given to precursor characteristics such as structural similarity to the desired product and the chemical homogeneity of the precursor species. For multicomponent films, this latter factor is believed to influence the interdiffusional distances associated with the formation of complex crystal structures, such as perovskite compounds. Synthetic approaches have been geared toward the preparation of multimetal species with cation stoichiometry identical to that of the desired crystalline phase.40 42 83 84... 

Storage of chemicals, 385 Strained-ring compounds, 385 Styrene—butadiene rubber, 386 Sugars, 386 Sulfinyl azides, 387 Sulfonation incidents, 387 Sulfonic acid esters, 388 Sulfonyl azides, 388 Sulfur black, 389 Sulfur compounds, 389 Sulfur esters, 389 Sunspots, 390 Superheated liquids, 390 Superiors/supervisors, 390 Synthetic perovskite oxides, 391... 

From a practical point of view, these compounds are models of crystalline matrices for nuclear waste disposal. One such storage material is SYNROC, a synthetic mineral whose major constituents are the complex oxides hollandite, zirconolite, and perovskite. We have chosen perovskite as a model structural family because of its efficient packing and its accommodation of a wide range of cations, both in size and oxidation state (5). 

Lanthanides as components in complex oxide systems In perovskites For conduction in electrocatalysis For oxidizing properties For hydrogenation properties For synthetic gas (CO-H2) reactions To provide sulfur oxides (SO, ) control In oxysulphides In other systems ... 

Tarascon JM, Greene LH, McKirmon WR, Htrll GW, Geballe TH (1987) Superconductivity at 40 K in the oxygen-defect perovskites La2 cSr Cu04 y. Science 235 1373-1376 Taylor M, Brown GE (1976) High-temperatrrre structrrral study of the P2 /a-A2/a phase transition in synthetic titanite, CaTiSiOs. Am Mineral 61 435-447... 

The structure of perovskite type is the archetype of numerous synthetic and natural compounds with stoichiometry ABX and their derivative structures. The latter are formally obtained from the archetype through mechanisms such as anion or... 

In a much later stage of development, other ceramics that were not clay-or silicate-based depended on much more sophisticated raw materials, such as binary oxides, carbides, perovskites, and even completely synthetic materials for which there are no natural equivalents. The microstructures of these modern ceramics were at least an order of magnitude finer and more homogeneous and much less porous than those of their traditional counterparts. It is the latter — the modern or technical ceramics — with which this book is mainly concerned. 

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