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Bismuth-layered structured ceramics Ca(Li,Ce)BiTiNbO-0.01MnCO were prepared by the conventional solid-state reaction method. The evolution of microstructure and corresponding electrical properties were studied. All the samples presented a single bismuth layered-structural phase with m = 4, indicating that (Li, Ce), Nb and Mn adequately enter into the pseudo-perovskite structure and form solid solutions. It was found that Ca(Li,Ce)BiTiNbO-0.01MnCO (CBTLCM-0.02Nb) ceramics possess the optimum electrical properties. The piezoelectric coefficient d, dielectric constant ε, loss tan δ, planar electromechanical coupling factor k and Curie-temperature T of CBTLCM-0.02Nb ceramics were found to be ∼19.6 pC/N, 160, 0.16%, 8.1% and 767°C, respectively. Furthermore, the thermal depoling behavior demonstrates that the d value of x = 0.02 content remains at 16.8 pC/N after annealing at 500°C. These results suggest that the (Li, Ce)-, Nb- and Mn-doped CBT-based ceramics are promising candidates for high-temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

(Li, Ce) and Mn modified CaBiTiO (CBT) based ceramics were prepared by the solid state route, and were substituted by the equimolar ions of Nb, Ta and W in the B-site. The variations of crystalline structure, microstructure, piezoelectric properties and dielectric properties were investigated. The XRD patterns indicated that all compositions formed a single bismuth layered-structural phase with m = 4. The additions of NbO, TaO and WO into CBT-based ceramics were found to affect the electrical properties and temperature stability of the ceramics. Compared with TaO and WO, the Nb-substitued ceramics exhibited the optimum piezoelectric property and dielectric property ( d ~ 19.6 pC/N, ε ~ 123.7 and tan δ ~ 0.1 %) among all of these samples, together with a high Curie-temperature ( T ~ 767.6 °C). Thermally activated depolarization behavior also demonstrated that the Nb doped CBT-based ceramics possess outstanding thermal stability of piezoelectric properties. These results indicated that NbO has a substantial effect on the structure and properties of CBT-based ceramics compared to TaO and WO. [ABSTRACT FROM AUTHOR]

Ca(Li,Ce)BiNbWO ( x = 0.01-0.06) high-temperature piezoceramics were prepared by a conventional solid-state sintered method, and effects of W content on their piezoelectric properties were studied. All samples possess a pure Aurivillius-type structure, showing that Li, Ce, and W dopants have well diffused into the CaBiNbO lattice to form a solid solution. The doping with W slightly decreases the Curie temperature ( T) of the ceramics. In addition, the excellent electrical properties (e.g., d ~ 16.1 pC/N, k ~ 9.58 %, Q ~ 4,767) and a high Curie temperature (e.g., T ~ 925 °C) are simultaneously obtained in the ceramics with x = 0.04, together with an enhanced thermal stability of <900 °C. As a result, the investigated material system provides the promising potential applications in ultra-high-temperature environments. [ABSTRACT FROM AUTHOR]