Large electric‐field‐induced strain and enhanced piezoelectric constant in CuO‐modified BiFeO3‐BaTiO3 ceramics

Abstract In this work, we fabricated the (1‐ x )BiFeO 3 ‐ x BaTiO 3 + y ‰ mol CuO ceramics by the modified thermal quenching technique. The pure perovskite phase was formed and a morphotropic phase boundary ( MPB ) was observed in the ceramics with x = 0.30‐0.33. The addition of CuO can significantly enhance the density of the BiFeO 3 ‐BaTiO 3 material. Importantly, an enhanced piezoelectric constant ( d 33 =165 pC /N), a large electric‐field‐induced strain (∆S = 0.54%: peak to peak strain) and a large piezoelectric actuator constant ( d 33 *=449 pm/V) together with a high Curie temperature ( T C ) of 503°C were observed in the ceramics with x = 0.30 and y = 5. As a result, the enhanced piezoelectricity and large electric‐field‐induced strain could significantly stimulate further researches in BFO ‐based ceramics.