Effect of the excess of bismuth on the morphology and properties of the BaBi2Ta2O9 ceramics
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Data
2005-03-01
Autores
Simoes, A. Z.
da Costa, GCC
Ramirez, M. A.
Varela, José Arana [UNESP]
Longo, Elson [UNESP]
Título da Revista
ISSN da Revista
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Editor
Elsevier B.V.
Resumo
In this study, the effect of bismuth content on the crystal structure, morphology and electric properties of barium-bismuth-tantalate (BBT) ceramics was explored with the aid of X-ray diffraction (XRD), scanning electron microcopy (SEM), dielectric properties and ferroelectric hysteresis loops. BaBi2Ta2O9 (BBT) ceramics have been successfully prepared by the solid-state reaction. The BBT phase was crystallized at 900 degreesC for 2 h. The excess of bismuth controls the grain size, affecting the density of the material. Measurements of dieletric constant and dieletric losses confirm that the material is a ferroeletric with a Curie temperature around 77 degreesC. The dieletric constant measured at room temperature was 400, with a dielectric loss of 0.03. Both the phase-transition behaviour and ferroelectric properties, such as spontaneous polarization (P-s), showed a dependence on Bi content. (C) 2004 Elsevier B.V. All rights reserved.
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Palavras-chave
ceramics, electrical properties, fatigue, sintering
Como citar
Materials Letters. Amsterdam: Elsevier B.V., v. 59, n. 6, p. 656-661, 2005.