Large strain and reduced hysteresis of BiFeO3-xBaTiO3 lead-free ceramic via multiphase coexistence and relaxor behaviors

Abstract

Ferroelectric ceramics with large strain response, low hysteresis and high Curie temperature (TC) are required for contemporary displacement actuator. In this work, (1-x)BiFeO3-xBaTiO3 ceramics were synthesized using traditional solid sintering technique. A high electric field-induced strain (0.25%), a relatively low hysteresis (22.5%) and a high Curie temperature (415 °C) were achieved in BiFeO3-0.35BaTiO3 ceramic. Meanwhile, the ceramics exhibited apparent relaxor behavior owing to the local structural heterogeneity. Aberration-corrected scanning transmission electron microscopy revealed that polar nano-regions with multiphase coexistence occur in the material, which is the microstructure origin of the enhanced strain and low hysteresis in BiFeO3-0.35BaTiO3 ceramics. This work indicates that BiFeO3–BaTiO3-based ceramics are good high-temperature ferroelectric materials and are promising candidates for high-precision actuator.