Ferroelectric domain evolution in a Ba(Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Ca_0.3)TiO₃ piezoceramic studied using piezoresponse force microscopy

Lead-free Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) ceramics have drawn attention in recent years because of their outstanding dielectric and electromechanical properties, such as a piezoelectric coefficient d33 ? 620 pC N?1 large signal d33* 1100 pm V?1 at 0.5 kV mm?1 room temperature (RT). These particular properties are relevant to range applications. However, the structural origin this high is still subject discussion. An in-depth understanding ferroelectric domain evolution BZT-0.5BCT crucial for probing underlying mechanisms guiding practical Using piezoresponse force microscopy (PFM), we directly visualized structure using electric field stimulation on micrometer nanometer scales. The PFM results unambiguously evidence coexistence wedge-shaped lamellar domains with miniaturized nanodomain structures RT. temperature- electric-field-dependent study presented here highlights critical role evolution. Wedge-shaped turn into small curved walls after heating cycle then become poling Transitional an increased density nanodomains appear both thermal cycles. More interestingly, different temperatures shows better reversibility than close phase boundary. This demonstrates that ceramic has superior stability medium (40 °C–60 °C), implying excellent