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The bismuth layer-structured ferroelectrics (BLSF) are promising high-temperature piezoelectric materials, in which large piezoelectricity, good thermal stability and high electrical resistivity are desired. Here highly textured CaBi 4 Ti 4 O 15 BLSF ceramics with orientation factor of 82% have been fabricated by spark plasma sintering technique. The piezoelectric coefficient d 33 is significantly enhanced by 250%, from 7.2 pC/N for the texture-less sample to 25.3 pC/N for the textured one, accompanied by a high Curie temperature T C = 788 °C. The variation of d 33 is below 5% in the temperature range of 25–500 °C, showing excellent thermal stability. The textured sample exhibits high electrical resistivity ρ = 2.1 × 1011 Ω·cm, an order of magnitude larger than that of the texture-less sample. At the temperature as high as 500 °C, the textured sample still maintains excellent electrical properties of d 33 = 24.2 pC/N, tan δ = 9.9% and ρ = 2.7 × 106 Ω·cm, suggesting that the textured CaBi 4 Ti 4 O 15 ceramics could be a potential candidate for high-temperature piezoelectric sensor or detector applications. • Textured CaBi 4 Ti 4 O 15 ceramics are fabricated by spark plasma sintering technique. • Piezoelectricity is enhanced by 250% without reducing Curie Temperature. • Large piezoelectricity, low loss and high resistivity are maintained at 500 °C. [ABSTRACT FROM AUTHOR]

For researching lead-free piezoelectric ceramics, (K 0.43 Na 0.52 Li 0.05)Nb 0.91 Sb 0.045 Ta 0.045 O 3 - x %mol Eu 2 O 3 ceramics are prepared via solid state reaction method. Piezoelectric, photoluminescence properties of the ceramics are studied. The typical effects of "soft" doping are observed. Well piezoelectric and ferroelectric properties are achieved at x = 0.3(d 33 = 252±6 pC/N, P r = 24μc/cm2, Strain = S max / E max = 0.166% at 4 kV/mm). Comparable d 33 are achieved after P-E test for sample x = 0.1–0.3. Better strain (0.177% at 4 kV/mm) and temperature stability are obtained when x = 0.4. Photoluminescence are introduced by Eu3+, and better photoluminescence with emission wavenumber 591 nm and 701 nm are detected when x = 0.5. • Eu enhances strain and its temperature stability of the KNN-based ceramics. • After P-E test well piezoelectric constants are achieved when Eu contents in a section of 0.1–0.3%mol. • As an electro-optical multifunctional materials, Eu doped KNN-based ceramics may have potential applicability. [ABSTRACT FROM AUTHOR]