Entirely aqueous solution-gel route for the preparation of (Pb 1-xCax)TiO3 thin films
[EN] In this work, calcium-modified lead titanate (Pb1-xCa x)TiO3 (PCT) precursor solutions with different amounts of Ca2+ substituting Pb2+ (x = 0.24 and 0.50) have been prepared for the first time by an entirely aqueous solution-gel route. The use of water as a nonhazardous and inexpensive solvent...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/345986 |
| Acceso en línea: | http://hdl.handle.net/10261/345986 |
| Access Level: | acceso abierto |
| Sumario: | [EN] In this work, calcium-modified lead titanate (Pb1-xCa x)TiO3 (PCT) precursor solutions with different amounts of Ca2+ substituting Pb2+ (x = 0.24 and 0.50) have been prepared for the first time by an entirely aqueous solution-gel route. The use of water as a nonhazardous and inexpensive solvent, together with the easy handling of the technique (no inert atmosphere is required), are the major advantages of this method. A stable citrato-peroxo complex of Ti(IV) was synthesized first and subsequently combined with the Pb2+ and Ca 2+ reagents (citrates) in the desired molar ratio to obtain the aqueous precursor solutions. The stability of these solutions with time is slightly influenced by the amount of Ca2+ introduced in the PCT system. Gels were obtained from these solutions and subjected to thermogravimetric analysis coupled on-line to Fourier transform infrared (TGA-FTIR) and mass spectroscopy (TGA-MS) techniques. To prepare thin films, we had to improve the hydrophilicity of the Pt/TiOx/SiO2/Si substrates and hence their wetting by the aqueous solutions using a wet chemical treatment of cleaning. Crystallization of the films was carried out by rapid thermal processing (RTP) in air at 650 °C. Films with a single perovskite phase and a homogeneous microstructure were thus obtained, as deduced by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The ability of this solution method to obtain PCT films with ferroelectric and dielectric responses is also demonstrated in the present work. © 2006 American Chemical Society. |
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