Role of the Addition of Pb(Li1/4Fe1/4W1/2)O3 in the Low-Temperature Sintering and Dielectric Characteristics of Pb(Mg1/3Nb2/3)
| Autor: | Wen-Shin Hwang, Chung-Hsin Lu |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Materials science
Analytical chemistry Pyrochlore Mixing (process engineering) Sintering Mineralogy General Chemistry Dielectric engineering.material Condensed Matter Physics Microstructure visual_art Phase (matter) Materials Chemistry Ceramics and Composites visual_art.visual_art_medium engineering Ceramic Perovskite (structure) |
| Zdroj: | Journal of the Ceramic Society of Japan. 104:587-593 |
| ISSN: | 1882-1022 0914-5400 |
| Popis: | The sintering behavior and dielectric characteristics of Pb(Li1/4Fe1/4W1/2)O3-added Pb(Mg1/3Nb2/3)O3 ceramics were investigated. Mixing the two end-members for 4h only formed a mixture, however, 48h-mixing mechanochemically induced the reactants to form partial perovskite solid-solutions. In the mixture specimen, the melt of Pb(Li1/4Fe1/4W1/2)O3 acted as a reactive liquid phase to substantially enhance the densification of Pb(Mg1/3Nb2/3)O3, and caused grains to grow greatly and resulted in nonuniform microstructure. Regardless of mixing conditions, pure perovskite solid-solutions were formulated at 1000°C when the content of Pb(Li1/4Fe1/4W1/2)O3 was less than 10 mass%, whereas, adding excess Pb(Li1/4Fe1/4W1/2)O3 unfavorably caused polyhedral pyrochlore phase to form in the matrix. The addition of Pb(Li1/4Fe1/4W1/2)O3 decreased the broad maximum of dielectric permittivity of sintered specimens; nevertheless, this addition markedly suppressed the temperature dependence of dielectric permittivity. The ceramics fabricated by the mixture of two end-members possessed a larger apparent diffusiveness of dielectric permittivity than those prepared from the partial solid-solution, implying that a wider compositional fluctuation likely occurred in the former specimen. |
| Databáze: | OpenAIRE |
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