Enhanced ferroelectricity of CaBi2Nb2O9-based high-temperature piezoceramics by pseudo-tetragonal distortion

The structure and electrical properties of Ca0.6(Li0.5Bi0.5‐xPrx)0.4Bi2Nb2O9 high‐temperature piezoelectric ceramics

“…A similar phenomenon was discovered in our previous studies and in other studies. 24,25 The most intense diffraction peak obtained for these samples was the (115) plane, which agrees with the fact that the most intense diffraction peak of BLSFs occurs for the (112m + 1) plane. 30,40 Moreover, the relative diffraction intensities of the (0010) and (008) peaks in Figure 2C increased gradually with an increase in the Pr 3+ content when 0 ≤ x ≤ 0.10, and the maximum intensities were obtained at x = 0.10, which suggests that Pr modification induces the preferential growth of grains along the c-axis.…”

“…The lattice parameters a and c tended to decrease with increasing Pr 3+ content, while b presented the opposite trend. Consequently, the a/b ratio decreased and approached unity, which indicates that the tetragonality of the crystal structure increased, 24,41 as was shown by the emergence of the (200)/(020) peaks in the XRD patterns. A similar phenomenon was observed in our previous works.…”

“…The raw starting materials including Bi 2 O 3 (99.999%), CaCO 3 (99%), Nb 2 O 5 (99.99%), Li 2 CO 3 (99.99%), and Pr 6 O 11 (99.9%), were weighed according to the desired stoichiometric compositions, and the detailed preparation steps can be seen in our previously published research. 24 The crystal structure of the as-sintered ceramics was determined by X-ray diffraction (XRD) using a diffractometer with Cu Kα radiation (DX2700). The powder XRD data were collected by using a powder X-ray diffractometer (X′ pert Pro, Panalytical).…”

“…11 Various strategies, including A-site or B-site cation modification, different sintering methods and textured techniques, were applied to improve the electrical properties of CBN. 6,11,[24][25][26][27][28][29][30] For instance, it was found that a solid solution of CaBi 2 Nb 2 O 9 and Li 0.5 Bi 2.5 Nb 2 O 9 with the formula Ca 0.6 (Li 0.5 Bi 0.5 ) 0.4 Bi 2 Nb 2 O 9 was found to possess greatly enhanced ferroelectric (2P r = 10 µC/cm 2 ) and piezoelectric (d 33 = 15.3 pC/N) properties but a relatively poor DC resistivity of 10 5 Ω cm at 600°C, as presented in our previous works. 24,31 Additionally, many investigations have discovered that exchanging the A-site Bi 3+ ions with lanthanide ions (La 3+ , Pr 3+ , Nd 3+ , etc.)…”

Enhanced electrical properties related to structural distortion of CaBi2Nb2O9‐based piezoelectric ceramics

“…For the STW‐2.5, the remanent polarization (2 P r ) was 10 μC/cm 2 . The enhanced ferroelectricity of this kind of Sr‐modified CBN‐based high‐temperature piezoelectric ceramics might be related to the enhanced tetragonality of lattice structure, which might facilitate the switching of polarization …”