QUANTITATIVE MICROSTRUCTURAL ANALYSIS AND PIEZOELECTRICITY OF HIGHLY DENSE, SUBMICRON-STRUCTURED NaNbO3 CERAMICS FROM MECHANICALLY ACTIVATED PRECURSORS
We study in this work the processing of NaNbO3 ceramics prepared in a single thermal treatment of highly reactive precursors obtained by mechanical activation of different reagents, aiming to determine optimum conditions for piezoelectric ceramics production. Pressure-less sintering at 1200ºC leads...
| Autores: | , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2011 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/41107 |
| Acesso em linha: | http://hdl.handle.net/10261/41107 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Quantitative Microstructural Analysis Análisis Microestructural Cuantitativo Sodium Niobate Sodio Niobato Ceramic Cerámica Piezoelectricity Piezoelectricidad Mechanical Activation Activación Mecánica |
| Resumo: | We study in this work the processing of NaNbO3 ceramics prepared in a single thermal treatment of highly reactive precursors obtained by mechanical activation of different reagents, aiming to determine optimum conditions for piezoelectric ceramics production. Pressure-less sintering at 1200ºC leads to dense ceramics (<5% porosity) with poor mechanical stability, unsuitable for practical uses. Dense hot pressed ceramics were also obtained at lower temperatures (900-1100ºC), all of them in the submicron range of average grain sizes (< 400 nm). Their microstructure was quantitatively characterised and their elastic and electromechanical properties determined by an automatic iterative method from impedance measurements at resonance. A noticeable ensemble of piezoelectric and elastic properties (d33=38 pC.N-1 and Np=3252 kHz.mm) was measured for hot pressed ceramics, from precursors obtained by a combined route of wet-chemistry and mechanical activation, with a microstructure characterized by 0.4% residual porosity and a bimodal lognormal distribution of grain size. |
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