Microstructure, dielectric, and piezoelectric properties of BiFeO₃–SrTiO₃ lead‐free ceramics

Abstract

BiFeO3‐SrTiO3 (BF‐ST) ceramics have been considered as a novel class of lead‐free dielectric materials exhibiting notable dielectric constants and remarkable thermal stability. In this work, we fabricated a series of (1‐x)BF‐xST (0.32≤x≤0.44) ceramics near the morphotropic phase boundary and comprehensively investigated their microstructure and electrical properties, which seeks to optimize the piezoelectric performance. As the ST content increases, a gradual reduction in the rhombohedral phase fraction is observed alongside a corresponding increase in the cubic phase fraction. While x = 0.38, the maximum grain size of 5.66 μm is obtained, accompanied by a distinctive heterogeneous core‐shell microstructure, which demonstrates a high remanent polarization of 51.2 μC/cm2 and a maximum d33 value of 72 pC/N. Furthermore, impedance spectroscopy analysis reveals the formation of a conductive core and a non‐conductive shell within the sample. These findings highlight the potential of optimized BF‐ST ceramics as promising alternatives to lead‐based piezoelectric materials, offering exceptional ferroelectric and piezoelectric properties.This article is protected by copyright. All rights reserved

Multifunctional Experimental Studies of Sm-Ion-Influenced Pseudo-Cubic Morphotropic Phase Boundary Regional BiFeO3-xSrTiO3 Ceramics for High-Temperature Applications

“…Makarovic et al have reported a d 33 of 69 pC/N for BF-0.375ST ceramics and a P r of ~30-50 µC/cm 2 [20]. Recently, Wang et al fabricated BF-0.38ST ceramics to exploit the MPB region and reported a P r of 51.2 µC/cm 2 and a d 33 of 72 pC/N [21], which is the maximum reported to date according to the best of our knowledge.…”