Temperature-induced changes in crystal lattice of bioaragonite of Tapes decussatus Linnaeus (Mollusca: Bivalvia)
| Autor: | J. Nemliher, K. Tõnsuaadu, T. Kallaste |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Calcite
Aragonite Analytical chemistry Infrared spectroscopy Crystal structure engineering.material Condensed Matter Physics Thermogravimetry chemistry.chemical_compound Lattice constant chemistry Differential thermal analysis engineering Orthorhombic crystal system Physical and Theoretical Chemistry |
| Zdroj: | Journal of Thermal Analysis and Calorimetry. 97:27-32 |
| ISSN: | 1572-8943 1388-6150 |
| Popis: | The characteristics of bioaragonite of shells of recent T. decussatus during heating were studied by the means of TG-DTA-EGA (FTIR), XRD, XRF and FTIR. The mass loss recorded up to 2.5% appeared with the higher rates at 110–150, 200–250, 295–300, and 390–415°C at heating of 10°C min –1 up to 500°C. IR analysis of the evolved gases revealed the emission of water and CO2. The lattice constants tend to change with anisotropy character (parameters a and c diminish whilst b tends to grows) and with an overall contraction of cell volume (from 227.36 to 226.84 3 ) during heating was established. The peculiarity of bioaragonite was explained by substitution of H2O and sulphate ion into the lattice. In spite of those substitutions, bioaragonite reveals an orthorhombic structure, which is preserved during the changes up to calcite formation above 380°C. |
| Databáze: | OpenAIRE |
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