Effect of Na/Ce codoping on the crystal structure and electrical properties of BaBi8Ti7O27 ferroelectric ceramics

Abstract

Ba(1-x)(Na0.5Ce0.5)xBi8Ti7O27 (BBIT:x(NC)) intergrowth bismuth layer-structured piezoelectric ceramics with enhanced piezoelectric and ferroelectric properties were synthesized by the traditional solid-state reaction process. Our systematic investigations show that the BBIT:x(NC) ceramics have a single intergrowth structure with an orthogonal phase. The reason of the internal bias field in BBIT:x(NC) ceramics was analyzed by atmosphere sintering, which was related to the defects of Na/Ce doped BBIT ceramics. Moreover, the electrical properties of Na/Ce co-doped BBIT ceramics were significantly improved. The sample with doping content x = 0.3 exhibits the most excellent piezoelectric constant d33 of 21.8 pC/N and a high Curie temperature Tc of 541 °C, which may be attributed to the enhancement of ferroelectric polarization and lattice mismatch, respectively. In addition, the remnant polarization (2Pr) was improved from 16.8 μC/cm2 to 20.2 μC/cm2, and the d33 was 20.6 pC/N after annealing at 450 °C, indicating that the ceramic samples had good thermal stability. Our results suggest that BBIT: 0.3(NC) ceramics may be a promising candidate for high-temperature piezoelectric applications.