A structural and thermogravimetric investigation of the rare-earth formates
| Autor: | LeRoy Eyring, Michael S. Jenkins, John M. Haschke, Rhéal P. Turcotte |
|---|---|
| Rok vydání: | 1970 |
| Předmět: |
Thermogravimetric analysis
Thermal decomposition chemistry.chemical_element Triclinic crystal system Condensed Matter Physics Lutetium Electronic Optical and Magnetic Materials Inorganic Chemistry Crystallography chemistry Materials Chemistry Ceramics and Composites Anhydrous Orthorhombic crystal system Physical and Theoretical Chemistry Single crystal Monoclinic crystal system |
| Zdroj: | Journal of Solid State Chemistry. 2:593-602 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/0022-4596(70)90056-3 |
| Popis: | Anhydrous rare-earth triformates (Sc, Y, LaTm) and triformate dihydrates (HoLu) have been prepared by direct reaction of the sesquioxides with aqueous formic acid. The thermal decomposition of anhydrous and thermally dehydrated formates, which have been investigated by TGA and high temperature X-ray diffraction techniques, and by mass spectrometric gas analysis is consistent with the following scheme: R(OOCH) 3 → R 2 O(OOCH) 4 → RO(OOCH) → R 2 O 2 CO 3 → R 2 O 3 (R designates a rare-earth atom). The monoxytetraformate appears to exist as an amorphous intermediate only for the lighter elements (La, Pr); the other intermediates are observed across the series except for ytterbium and lutetium, which exhibit more complex decomposition paths involving the pentoxymonocarbonate, R4O5CO3. Lattice parameters obtained from powder and single crystal X-ray diffraction data for rhombohedral R(OOCH)3 (Y, LaTm), hexagonal LaO(OOCH), orthorhombic (Pmma) R(OOCH)3·2H2O (Y, Ho, Er), triclinic R(OOCH)3·2H2O (Yb, Lu), and monoclinic ( P2 1 c ) Sc(OOCH)3 and linear thermal expansion data for Pr(OOCH)3 are presented. The preparative results, decomposition schemes, and structural data are discussed and compared with those of previous reports. |
| Databáze: | OpenAIRE |
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