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CaBi2Nb2O9 (CBN)‐based high Curie temperature piezoelectric ceramics with formula Ca0.8‐xSrx(Li0.5Ce0.15Bi0.35)0.2Bi2Nb1.94Ta0.04W0.02O9 were prepared by conventional solid‐state reaction method. The effects of strontium substitution for calcium in CBN pseudo‐perovskite structure A‐site were systematically studied. Results showed that the addition of Sr2+ ions lead to an improvement of the tetragonality of lattice structure, which resulted in an enhancement of piezoelectric and ferroelectric properties together with high Curie temperature TC and good resistance to thermal depolarization. The analysis of dielectric spectrums revealed that the space charge polarization induced an additional dielectric anomaly occurred below TC. The composition with x = 0.025 showed good integrated performance, the piezoelectric coefficient d33 and TC were ~17.5 pC/N and ~917°C, respectively. Even though the as‐studied ceramics underwent high depolarizing temperature reached up to 875°C, d33 decreased by 8% merely. The remanent polarization 2Pr and the resistivity ρ at 650°C were on the order of ~10 μC/cm2 and 3 × 105 Ω cm, respectively.

Effect of lattice occupation behavior of Li+ cations on microstructure and electrical properties of (Bi1/2Na1/2)TiO3-based lead-free piezoceramics W/Cr co-doped Bi 4 Ti 3 O 12 (BTWC) ceramics {Bi 4 Ti 3Àx W x O 12 þ x þ 0.2 wt. % Cr 2 O 3 (x ¼ 0-0.1)} with a high piezoelectricity were prepared by a conventional ceramic process, and effects of W/Cr dopant on the microstructures, dielectric, and piezoelectric properties of ceramics were explored. It is found that W 6þ modified the grain morphology and size of ceramics, promoting the forming of the regular schistose grains with a size of $10 lm in the ceramic at x ¼ 0.05. BTWC ceramics showed a continuous decrease in T c and a gradual increase in e r with the increasing W doping content. While the hard-doping of Cr 2 O 3 decreased, the TK e and tan d of ceramics available. All the ceramics keep the nature of first-order transition and displacive ferroelectrics. The d 33 and k p of BTWC ceramics were remarkably improved by the soft-doping of W 6þ . Excellent electrical properties (e.g., T c ¼ 638 C, e r ¼ 146, tan d ¼ 0.56%, TK e (500 C) ¼ 1.30 Â 10 À3 / C, s (500 C) ¼ 4.08 Â 10 À5 s, d 33 ¼ 28 pC/N, and k p ¼ 6.17%) have been achieved in Bi 4 Ti 2.95 W 0.05 O 12.05 þ 0.2 wt. % Cr 2 O 3 ceramic. Such a material can be a promising candidate for high-temperature piezoelectric applications. V C 2014 AIP Publishing LLC. [http://dx.

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