Crystallisation of Pb1-xCaxTiO3 ferroelectric thin films as a function of the Ca2+ content

[EN] 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 sub...

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Detalles Bibliográficos
Autores: Bretos, Íñigo, Ricote, J., Jiménez, Ricardo, Mendiola, Jesús, Jiménez Riobóo, R. J., Calzada, M. L.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2005
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/345956
Acceso en línea:http://hdl.handle.net/10261/345956
Access Level:acceso abierto
Palabra clave:Films (A)
Sol-gel processes (A)
X-ray methods (B)
Perovskites (D)
Calcium lead titanate.
Descripción
Sumario:[EN] 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. © 2005 Elsevier Ltd. All rights reserved.