(1 − x)(Bi,Na)TiO3−x(Ba,Sr)TiO3 lead-free piezoelectric ceramics for piezoelectric energy harvesting

Lead-free piezoelectric (1 − x )(Bi 0.5 Na 0.5 )TiO 3− x (Ba 0.5 Sr 0.5 )TiO 3 ( x = 0, 0.03, 0.06, 0.08, 0.12) ceramics were fabricated by using a conventional ceramic sintering method. The piezoelectric properties of (1 − x )(Bi 0.5 Na 0.5 )TiO 3− x (Ba 0.5 Sr 0.5 )TiO 3 lead-free ceramics were investigated. The crystallinity and the microstructure of (1 − x )(Bi 0.5 Na 0.5 )TiO 3− x (Ba 0.5 Sr 0.5 )TiO 3 ceramics were observed employing X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The morphotropic phase boundary (MPB) of the rhombohedral and the tetragonal phases was detected at x = 0.08 by using the XRD patterns. In addition, the piezoelectric and the dielectric properties of (1 − x )(Bi 0.5 Na 0.5 )TiO 3− x (Ba 0.5 Sr 0.5 )TiO 3 were characterized. A piezoelectric coefficient d33 of 118 pC/N, an electromechanical coupling factor k p of 35.17%, a generated output power of 17.15 nW, and a figure of merit of 2.85 pm 2 /N were obtained.