Volume 98, Issue 7 p. 2177-2182
Original Article

Temperature Stability of Lead-Free Niobate Piezoceramics with Engineered Morphotropic Phase Boundary

Ruiping Wang

Corresponding Author

Ruiping Wang

National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568 Japan

Author to whom correspondence should be addressed. e-mail: [email protected]Search for more papers by this author
Ke Wang

Ke Wang

State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084 China

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Fangzhou Yao

Fangzhou Yao

State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084 China

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Jing-Feng Li

Jing-Feng Li

State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084 China

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Florian H. Schader

Florian H. Schader

Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, Darmstadt, 64287 Germany

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Kyle G. Webber

Kyle G. Webber

Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, Darmstadt, 64287 Germany

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Wook Jo

Wook Jo

School of Materials Science and Engineering, Ulsan National Institute of Science and Engineering, Ulsan, 689-798 South Korea

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Jürgen Rödel

Jürgen Rödel

Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, Darmstadt, 64287 Germany

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First published: 23 April 2015
Citations: 137

Abstract

The temperature dependence of piezoelectric properties (direct piezoelectric coefficient d33, converse piezoelectric coefficient d33(E = 0), strain S and electromechanical coupling coefficient kp) for two niobate-based lead-free piezoceramics have been contrasted. 0.92(Na0.5K0.5)NbO3–0.02(Bi1/2Li1/2)TiO3–0.06BaZrO3 (6BZ/2BLT/92NKN) has a morphotropic phase boundary (MPB) between rhombohedral and tetragonal at room temperature and 0.92(Na0.5K0.5)NbO3–0.03(Bi1/2Li1/2)TiO3–0.05BaZrO3 (5BZ/3BLT/92NKN) features an MPB engineered to be located below room temperature. At 30°C, d33d33(E = 0), S (at 2 kV/mm), and kp are 252 pC/N, 230 pm/V, 0.069%, 0.51 for 5BZ/3BLT/92NKN; and 348 pC/N, 380 pm/V, 0.106%, 0.57 for 6BZ/2BLT/92NKN, respectively. With increasing temperature, the piezoelectric properties decrease. At 200°C, d33, d33(E = 0), S (at 2 kV/mm), and kp are 170 pC/N, 160 pm/V, 0.059%, 0.36 for 5BZ/3BLT/92NKN; and 181 pC/N, 190 pm/V, 0.061%, 0.39 for 6BZ/2BLT/92NKN. It is found that the electromechanical coupling coefficient has a better temperature stability than the piezoelectric coefficient in the studied system due to a large temperature-dependent compliance change. The results demonstrate that engineering an MPB is highly effective in tailoring temperature stability of piezoceramics.