Dielectric and Electromechanical Properties of Textured Niobium-Doped Bismuth Titanate Ceramics |
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Authors: | Seong-Hyeon Hong Susan Trolier-McKinstry Gary L. Messing |
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Affiliation: | Materials Research Laboratory and Particulate Materials Center, The Pennsylvania State University, University Park, Pennsylvania 16802 |
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Abstract: | Textured Nb-doped bismuth titanate ceramics (Bi4Ti3− x /5- Nb x /5O12, where x = 0.02) were fabricated by templated grain growth. It was found that the use of a fine precursor powder led to enhanced densification of the ceramic, while Nb doping reduced electrical conduction and dielectric loss, which enabled poling at high temperatures and high electric fields. Sintered tapes showed anisotropic dielectric and piezoelectric properties when measured parallel and perpendicular to the casting plane (e.g., the remanent polarization differed by more than a factor of 15 in the two directions). The piezoelectric constant parallel to the casting plane of the tape was ∼30 pC/N, or ∼77% of the single-crystal value. Thermal depoling studies demonstrated that high-temperature piezoelectric applications are possible up to ∼450°C in textured, doped bismuth titanate. |
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Keywords: | dielectric properties electromechanical properties bismuth titanate |
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