Structure and piezoelectric properties of new ternary K 0.5Na 0.5NbO 3-LiSbO 3-CaTiO 3 lead-free piezoceramics

New ternary (1-x)K 0.5Na 0.5NbO 3-x(0.80LiS- bO 3-0.20CaTiO 3) lead-free ceramics were fabricated by a conventional ceramic technique and their structure and piezoelectric properties were studied. The results of X-ray diffraction reveal that LiSbO 3 and CaTiO 3 diffuse into the K 0.5Na 0.5NbO 3 lattices to form a new solid solution with a perovskite structure. After the addition of LiSbO 3 and CaTiO 3, the cubic-tetragonal and tetragonal-orthorhombic phase transitions shift to lower temperatures. Coexistence of the orthorhombic and tetragonal phases is hence formed in the ceramics with 0.03 < × < 0.07 at room temperature, leading to a significant enhancement of the piezoelectric properties. For the ceramics with × = 0.04-0.06, the piezoelectric properties become optimum: d 33 = 172-253 pC/N, k P = 49.9-55.5%, k t = 49.2-52.1% and T C = 348-373 °C. The ceramic with × = 0.04 also exhibits a good thermal stability of piezoelectric properties.Department of Applied Physic