| Autor: |
M. L. Calzada, Jesús Ricote, Iñigo Bretos, J. Mendiola, R. J. Jiménez Riobóo, Ricardo Jiménez |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Journal of the European Ceramic Society. 25:2325-2329 |
| ISSN: |
0955-2219 |
| DOI: |
10.1016/j.jeurceramsoc.2005.03.051 |
| Popis: |
Lead calcium titanate (Pb1−xCaxTiO3) thin films with x from 0 to 0.50 were prepared by chemical solution deposition. Crystallinity of the films was studied as a function of calcium content and processing temperature. These studies were carried out on films deposited onto oxidised (1 0 0) Si substrates by means of X-ray diffraction. The analysis seems to indicate that the grain size of the films decreases as Ca2+ content increases, which was confirmed from the scanning force microscopy images of the films. X-ray data reveal that kinetics of grain growth in films with Ca2+ contents over 40 at% is very slow. Increase of calcium also produces a decrease in tetragonality of the perovskite films. Besides, it was observed that reflections of the perovskite appear at higher temperature in the films with larger Ca2+ contents. Brillouin spectroscopy was used to follow the evolution of the elastic properties of the films with temperature. This study shows an elastic instability at temperatures between 475 °C and 500 °C that can be associated to complete film crystallisation. Dielectric and ferroelectric properties were measured on films deposited onto platinised silicon substrates and crystallised at 650 °C. The films with 50 at% of Ca2+ still have ferroelectric properties, showing diffuse ferro-paraelectric transitions and slim ferroelectric hysteresis loops. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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