Collaborative Optimization of Curie Temperature and Piezoelectricity in Ternary BiFeO₃–BiScO₃–PbTiO₃

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- x )BiFeO 3 – x BiScO 3 –0.32PbTiO 3, with varied addition of BiScO 3 ( x = 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 x = 0.10 BiScO 3 addition, of which the piezoelectricity was found to be seven times larger than that without BiScO 3 (∼208 pm/V vs ∼38 pm/V). Most importantly, a high Curie temperature of 430 °C is successfully inherited from binary 0.68BiFeO 3 –0.32PbTiO 3 . 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 3 –BiScO 3 –PbTiO 3 film with integrated prominent performance for potential applications at elevated temperatures.