Paraelectric Matrix-Tuned Energy Storage in BiFeO3-BaTiO3-SrTiO3 Relaxor Ferroelectrics

Incorporation of polymorphic ferroelectric nanodomains into a paraelectric matrix has been proven to be effective to achieve high energy storage density in a relaxor ferroelectric system. In this work, we fabricated short-range ordered polymorphic 0.20BiFeO(3)-(0.80 - x)BaTiO3 nanodomains in a paraelectric xSrTiO(3) host (0.40 <= x <= 0.65) to form ternary relaxors with transition temperatures in the range of 425-460 degrees C. The addition of SrTiO3 suppresses the P-E loops of the binary BiFeO3-BaTiO3 system and improves the recoverable energy and energy storage efficiency. A well-sintered solid solution exhibits nearly ideal relaxor ferroelectric behavior for x = 0.50, which demonstrates the highest tetrahedral c/a ratio (1.0042), saturation polarization (26.39 mu C/cm(2)), breakdown strength (183.1 kV/cm), and recoverable energy (2.15 J/cm(3) at 190 kV/cm) and also shows high current density, high power density, and short discharge time. The overall evolution of the c/a ratio, saturation polarization, and recoverable energy follows an x-dependent volcanic shape, while the variation of residual polarization is x-independent. The maximum energy storage efficiency of 95.56% is observed for x = 0.55 at 200 kV/cm. These findings suggested that the 0.20BiFeO(3)-(0.80 - x)BaTiO3-xSrTiO(3) system is promising for dielectric energy storage applications.

Automated summary

Incorporating polymorphic ferroelectric nanodomains into a paraelectric matrix can enhance energy storage density in relaxor ferroelectric systems. The addition of SrTiO3 to a binary BiFeO3-BaTiO3 system suppresses P-E loops and improves recoverable energy and energy storage efficiency. The system of 0.20BiFeO(3)-(0.80 - x)BaTiO3-xSrTiO(3) shows promising potential for dielectric energy storage applications, with high energy storage efficiency observed at x = 0.55.