Collaborative Optimization of Curie Temperature and Piezoelectricity in Ternary BiFeO-BiScO-PbTiO.

The enhancement of piezoelectricity without compromising the Curie temperature of a piezoelectric is challenging due to phenomenological incompatibility. In the present work, the phase diagram of (0.68-)BiFeO-BiScO-0.32PbTiO, with varied addition of BiScO ( = 0, 0.05, 0.10, 0.15, and 0.20), was constructed through systematic studies of the dielectric, ferroelectric, and piezoelectric properties. A rhombohedral-tetragonal phase boundary was observed near = 0.10 BiScO addition, of which the piezoelectricity was found to be seven times larger than that without BiScO (∼208 pm/V vs ∼38 pm/V). Most importantly, a high Curie temperature of 430 °C is successfully inherited from binary 0.68BiFeO-0.32PbTiO. This is explained by optimized Bi compensation, which is observed critical regulating Curie temperature in BFO-based binary and ternary systems. These results open up a paradigm for collaboratively optimizing the Curie temperature and piezoelectric response for a number of ferroelectrics and provide a promising BiFeO-BiScO-PbTiO film with integrated prominent performance for potential applications at elevated temperatures.