Effect of Iron Oxide on the Dielectric and Piezoelectric Properties of (K 0.5 Na 0.5 )(Nb 0.96 Sb 0.04 )O 3 Ceramics

()()+1.2 mol% ceramics doped with iron oxide () were prepared by a conventional mixed oxide method. And then, their piezoelectric and dielectric properties were investigated as a function of addition. X-ray diffraction studies reveal that diffuses into the NKN lattices to form a solid solution with a pure perovskite structure at room temperature. At the sintering temperature of , when 0.2 mol% was doped, the piezoelectric constant (), electromechanical coupling factor (Kp), and mechanical quality factor () showed the excellent values of 131.67 pC/N, 0.436, and 696.36, respectively. Results show that deped ()()+1.2 mol% lead-free piezoelectric ceramics are a promising lead free material for piezoelectric transformer applications.