Autor: |
Meriem Meyar, Laldja Taïbi-Benziada |
Rok vydání: |
2007 |
Předmět: |
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Zdroj: |
Journal of the European Ceramic Society. 27:1097-1100 |
ISSN: |
0955-2219 |
Popis: |
Mixtures of (1-x)BaTiO 3 +xSrF2 +xLiF are prepared and dry-ground. The powders thus obtained are shaped to discs and sintered in free-air at 950 °C for 2 h. The shrinkage coefficient varies between 14.5% and 16.8%. The XRD patterns show the formation of a new solid solution with general formula Ba 1-x Sr x (Ti 1-x Li x )O 3-3x F 3x which occurs in the composition range 0 ≤ x ≤ 0.25. The ceramic grain size is observed by Scanning Electron Microscopy (SEM) on fractured samples. The phase transitions in these perovskite-type oxifluorides are investigated by Differential Scanning Calorimetry (DSC) and dielectric measurements. The sintering temperature (t sint ≈ 1400°C) and the ferroelectric Curie temperature (T C ≈ 120 °C) of BaTiO 3 are strongly lowered by the triple substitution Ba-Sr, Ti-Li and O-F. The value of T C for Ba 0.95 Sr 0.05 (Ti 0.95 Li 0.05 )O 2.85 F 0.15 is around -65 °C. These new phases are suitable for the fabrication of capacitors in various microelectronic devices. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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