Enhanced ferroelectric and piezoelectric properties in SnO₂ modified Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ lead-free ceramics

Abstract

Lead-free piezoelectric ceramic (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ + xSnO₂ (BCZT + xSnO₂, for short) (x = 0, 0.004, 0.008, 0.012 and 0.016) system with remarkable electrical properties was prepared via the solid state reaction method. The roles of SnO₂ addition on the structural and electrical properties were investigated. X-ray diffraction showed that the perovskite structure was formed in all components. SEM images indicated that the addition of SnO₂ promoted grain growth in BCZT + xSnO₂ ceramics. Dielectric measurement revealed that the temperature of orthorhombic-tetragonal phase transition moved towards to higher temperature, while the temperature of tetragonal–cubic moved to lower temperature for the sample. The variation degree of temperature has a close relationship with the SnO₂ concentration. The outstanding electrical properties was obtained (P_r = 8.98 µC/cm², E_c = 1.21 kV/cm, d₃₃ = 656 pC/N, and strain = 0.090 %) with the sample of x = 0.012. The enhanced properties indicated that the (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ + xSnO₂ ceramics are promising for lead-free practical applications.