MnO2 doping induced structural tuning drives superior piezoelectric response in CaBi4Ti4O15-based ceramics

Abstract

Composition optimization and domain engineering modulation with diverse elements and structural tuning are favorable pathways that can be implemented to increase piezoelectric properties. Here, CaBi4Ti3.89(W1/2Co1/2)0.11O15+x wt%MnO2 (CBTWC–xMn, x = 0–0.25) ceramics with superior piezoelectric responses were prepared via a solid-state sintering method. The mechanism of the high piezoresponse was examined by integrating visual crystal structure analysis with piezoresponse force microscopy, revealing that the introduction of MnO2 led to greater distortion of the [TiO6] octahedron and a more oriented domain structure, both of which are critical factors contributing to the enhanced piezoelectric response. The optimized CBTWC–0.1Mn ceramics achieved an ultrahigh piezoelectric constant (d33 = 27.3 pC/N), which was 50% greater than that of the pure CBTWC ceramics. Furthermore, the CBTWC–0.1Mn ceramics exhibited better ferroelectric properties, a high Curie temperature (TC = 754.7 °C), low dielectric loss (tanδ = 6.7% at 500 °C), and excellent thermal stability, and their d33 (26.3 pC/N) maintained over 95% of its initial value after annealing at 500 °C. This work provides a feasible strategy for improving the properties of bismuth layer-structured piezoelectric ceramics, which has important prospects for the application of high-temperature piezoelectric devices.

Keywords

• bismuth layer-structured ceramics
• aurivillius phase
• high-temperature piezoelectrics
• cabi4ti4o15
• mno2 doping