Publication Date:
2011-04-02
Description:
In order to obtain dense PbNb 2 O 6 -based piezoelectric ceramics with a single orthorhombic ferroelectric phase, Ba, and excess Ti were doped into PbNb 2 O 6 ceramics with the composition of Pb 0.92 Ba 0.08 Nb 2 O 6 –0.25 wt% TiO 2 via a conventional solid-state reaction method. The ceramics were sintered at 1210°–1300°C. The effects of sintering temperature on the crystallite structure, microstructure, and dielectric and piezoelectric properties were studied in detail. All ceramics had shown a high relative density (〉94%) and a single orthorhombic phase. The lattice parameters, grain size, and shape varied with changing sintering temperature. All ceramics exhibited a typical characteristic in ferroelectrics with normal paraelectric–ferroelectric phase transition at the Curie temperature. With increasing sintering temperature from 1210° to 1300°C, the Curie temperature decreased from 554° to 523°C, while the maximum dielectric constant increased. The change in dielectric properties with changing sintering temperature is associated with a competing effect among internal stress, porosity, and grain size. The ceramic sintered at 1260°C possesses an excellent piezoelectric constant ( d 33 =82 pC/N), low mechanical quality factor ( Q m =20.52), low dielectric loss (tan δ=0.0062), and high Curie temperature ( T c =535°C), presenting a high potential to be used in high-temperature applications as piezoelectric transducers.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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