Structure and Dielectric Behavior of Yb<sub>2</sub>O<sub>3</sub>-MgO Co-Doped 0.92BaTiO<sub>3</sub>-0.08(Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> Ferroelectric Relaxor
Dielectric properties and structure of 0.015Yb<sub>2</sub>O<sub>3</sub>-<i>x</i>MgO doped 0.92BaTiO<sub>3</sub>-0.08(Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> ceramics with <i>x</i> = 0.0–0.025 hav...
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| Autores principales: | , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
MDPI AG
2021
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/e6ce29e544e24ec0bac9f8588cee85d4 |
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| Sumario: | Dielectric properties and structure of 0.015Yb<sub>2</sub>O<sub>3</sub>-<i>x</i>MgO doped 0.92BaTiO<sub>3</sub>-0.08(Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> ceramics with <i>x</i> = 0.0–0.025 have been investigated. As Yb<sub>2</sub>O<sub>3</sub>-MgO was added into the BT-NBT, the phase changes from tetragonal to pseudo-cubic, with the tetragonality <i>c</i>/<i>a</i> decreases from 1.011 to 1.008 and XRD peaks broadened. The combined study of XRD and TEM image revealed a formation of core–shell structure in grains with core of 400–600 nm and the shell of a thickness 60–200 nm. There is a slowly phase transition against temperature from the variable temperature Raman analysis. The ferroelectric relaxor peak of BT-NBT decreases from ~4000 to ~2000 and a new broad dielectric peak with an equivalent maximum (<i>ε</i><sub>r</sub>′~2300) appears in the temperature dependent dielectric constant curve (<i>ε<sub>r</sub></i>′-<i>T</i>), which produces a flat <i>ε<sub>r</sub></i>′-<i>T</i> curve. Sample 0.92BaTiO<sub>3</sub>-0.08(Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub>-0.015Yb<sub>2</sub>O<sub>3</sub>-0.005 MgO and 0.92BaTiO<sub>3</sub>-0.08(Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub>-0.015Yb<sub>2</sub>O<sub>3</sub>-0.01MgO give a <i>ε</i><sub>r</sub>′ variation within ±14% and ±10% in 20–165 °C. The core–shell microstructure should take account for the flattened <i>ε</i><sub>r</sub>′–<i>T</i> behavior of these samples. |
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