Decomposition of Spinel-Type Nickel Chromium Indium Sulfides—X-Ray Powder Structure Determination
| Autor: | H. D. Lutz, Ch. Kringe, Th. Stingl, K. Mohn |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Spinel
Inorganic chemistry Analytical chemistry chemistry.chemical_element Crystal structure engineering.material Condensed Matter Physics Decomposition Electronic Optical and Magnetic Materials Inorganic Chemistry Chromium Nickel chemistry X-ray crystallography Materials Chemistry Ceramics and Composites engineering Physical and Theoretical Chemistry Solid solution Phase diagram |
| Zdroj: | Journal of Solid State Chemistry. 136:193-198 |
| ISSN: | 0022-4596 |
| DOI: | 10.1006/jssc.1997.7675 |
| Popis: | The phase diagram of the quaternary system NiCr2S4–NiIn2S4–Cr2S3–In2S3has been studied at 873 and 1223 K by X-ray powder structure determination of quenched samples. At high temperatures, spinel-type Niy(Cr2−2xIn2x)1−yS3−2ysolid solutions are formed in a large range of composition (y: 0–0.5,x: 0.3–1). At temperatures below 1183 K, these solid solutions decompose to Cr-rich and In-rich spinel-type sulfides, whereby nickel is enriched in the Cr-rich compounds. The decomposition of the spinel-type sulfides is greatly retarded, even at temperatures about 900 K, due to both thermodynamic and kinetic reasons. The cation distribution established corresponds to a site preference as Cr3+>Ni2+>In3+at the octahedral 16d site and □ (vacancies)>In3+>Ni2+at the tetrahedral 8a site of the spinel structure. The metal-sulfur distances of the solid solutions refined are compared with those calculated from characteristic metal–sulfur distances in close-packed structures, taking into account the site occupation established. For the respective indium-sulfur distances, the following improved values are recommended: Intet–S=247.1 pm; Inoct–S=260.6 pm. |
| Databáze: | OpenAIRE |
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