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(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]

Abstract: Aurivillius type (LiCePr)-multidoped CaBi2Nb2O9 ceramics were prepared using the conventional mixed oxides route. The effects of the (LiCePr) additives on the structure and dielectric properties were studied. The piezoelectricity was significantly improved by the incorporation of (LiCePr) dopants. The Ca0.9(Li0.5Ce0.25Pr0.25)0.1Bi2Nb2O9 (CBN–LCP10) ceramics possess the optimum properties, and the d 33, k p and T C values were found to be ∼17.3pC/N, 7.8% and ∼939°C, respectively. The thermal depoling behavior and electromechanical properties at elevated temperature were studied in detail. Both results demonstrate that CBN–LCP10 ceramics possess a stable piezoelectricity in a wide temperature range, making CBN-based ceramics promising for high temperature applications. [Copyright &y& Elsevier]