Piezoelectric and ferroelectric properties of Ba0.9Ca0.1Ti0.9Sn0.1O3 lead-free ceramics with La2O3 addition

Lead-free Ba0.9Ca0.1Ti0.90Sn0.10O3-x La2O3 (x = 0-0.07 mol%) piezoelectric ceramics have been prepared at 1480 °C by conventional solid-state sintering process. The effects of La2O3 addition on the microstructure, the piezoelectric and dielectric properties have been investigated. X-ray diffraction pattern confirmed the coexistence of the orthorhombic phase and tetragonal phase at around x = 0.03. SEM images indicate that the addition of La2O3 restrain abnormal grain growth and lead to the formation of homogeneous microstructures during sintering. Main piezoelectric parameters are optimized at x = 0.03 with a high piezoelectric coefficient (d33 = 496 pC/N), a planar electromechanical coupling factor (kp = 41.7%), which indicates that the Ba0.9Ca0.1Ti0.90Sn0.10O3-x%La2O3 ceramics are promising for lead-free practical applications.