Properties of novel CaBi2Ta2O9-(Na0.5Bi0.5)Bi2Ta2O9 solid solution-based high Curie temperature piezoelectric ceramics

Designing ferroelectrics with excellent electrical performance and high-temperature electrical resistivity (rho) without severely sacrificing their high Curie temperature (T-C) is a major issue in the development of Bismuth Layer-Structured Ferroelectrics (BLSFs). In this regard, a novel solid solution of CaBi2Ta2O9 and Na0.5Bi2.5Ta2O9 was synthesized by conventional electroceramic procedures in this study and was found to possess enhanced piezoelectric and ferroelectric properties together with a high Curie temperature (T-C similar to 925 degrees C). Further addition of (Li0.5Ce0.5)(2+) not only elevated its piezoelectric constant (d(33) similar to 13.3 pC/N) and remnant polarization (P-r similar to 7.2 mu C/cm(2)) but also increased its high-temperature electrical resistivity (rho > 10(8) Omega.cm at 500 degrees C and similar to 10(7) Omega.cm at 600 degrees C) by more than one order of magnitude when compared with that of other BLSFs. Moreover, the CNBT-LC4 sample maintained 92% of its initial value after depoling at 900 degrees C and maintained its piezoelectric performance in the following annealing runs. These results demonstrate that Ca-0.5(NaBi)(0.25-x/2)(LiCe)(x/2)Bi2Ta2O9 ceramics are promising candidates for future applications. (c) 2019 Elsevier B.V. All rights reserved.