Electromechanical properties of ternary BiFeO3−0.35BaTiO3–BiGaO3 piezoelectric ceramics
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In the present work, composition dependent crystal structure, ferroelectric, piezoelectric, and temperature dependent dielectric properties of the BiGaO3-modified (1–x)(0.65Bi1.05FeO3–0.35BaTiO3) (BFBT35–xBG, where x = 0.00–0.03) lead-free ceramics were systematically investigated by solid-state reaction method, followed by water quenching process. The substitution of BG successfully diffuses into the lattice of the BFBT ceramics, without changing the pseudo-cubic structure of the samples. The scanning electron microscopy (SEM) results revealed that the average grain size was increased with BG-content in BFBT system. The BFBT–xBG ceramics showed a maximum in permittivity (ɛmax) at temperatures (Tmax) above 500 °C in the compositional range of 0.00 ≤ x ≤ 0.03. The electro-strain is measured to be 0.125% (d*33 ~ 250 pm/V) under unipolar fields (5 kV/mm) for BFBT–0.01BG ceramics. The same composition (x = 0.01), large static piezoelectric constant (d33 ~ 165 pC/N) and electromechanical coupling factor (kp ~ 25%) were obtained. The above investigated characterizations suggests that BFBT–BG material is favorable for piezoelectric and high temperature applications.
KeywordsLead-free Dielectric Ferroelectric Piezoelectric BiFeO3–BaTiO3
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), as funded by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2018R1A2B6005044) and also supported by the National Research Foundation of Korea (NRF-2018R1D1A1B07041634).