Polymorphism under pressure of the disilicates of the heavier lanthanoids Ln2Si2O7 (Ln = Tm, Yb, Lu)
| Autor: | C. Loriers, C. Chateau, J. Loriers, G. Bocquillon |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Ytterbium
Chemistry Mineralogy chemistry.chemical_element Triclinic crystal system Condensed Matter Physics Electronic Optical and Magnetic Materials Inorganic Chemistry Tetragonal crystal system Crystallography Thulium Materials Chemistry Ceramics and Composites Physical and Theoretical Chemistry Isostructural Monoclinic crystal system Ambient pressure Phase diagram |
| Zdroj: | Journal of Solid State Chemistry. 20:135-141 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/0022-4596(77)90060-3 |
| Popis: | A study of the phase diagram of thulium, ytterbium, and lutecium disilicates Ln2Si2O7 in the ranges 0–70 kbar and 20–1600°C shows the extended polymorphism under high pressure of these compounds of which only one form was previously known at ambient pressure. The monoclinic D form appears at temperatures much lower than for the neighboring members of the series and its stability field is restricted to a rather narrow pressure interval around 20 kbar. The triclinic B form appears at pressures which increase from 20 to 40 kbar from Tm to Lu. A new tetragonal X form so far unknown in the disilicate series and isostructural with Er2Ge2O7 is obtained for the three compounds. Compared to the B form it is a low temperature, low pressure form. The crystal data of the nine high pressure phases are given. |
| Databáze: | OpenAIRE |
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