Electrical properties of [Li0.04(K0.5Na0.5)0.96−xAgx](Nb1−ySby)O3 ceramics

Dependence of electrical properties on the structural characteristics of Li0.04(K0.5Na0.5)0.96(Nb1−ySby)O3 (LKNNS (x = 0, 0.00 ≤ y ≤ 0.10)) and [Li0.04(K0.5Na0.5)0.96−xAgx](Nb0.925Sb0.075)O3 (LKNANS (0.01 ≤ x ≤ 0.05, y = 0.075)) were investigated. The oxygen octahedral distortion was dependent on Ag+ and/or Sb5+ content which affected to the phase transition temperature of LKNNS and LKNANS ceramics. The orthorhombic–tetragonal and tetragonal–cubic phase transition temperatures (TO–T, TC) of the specimens were decreased with increasing of average octahedral distortion. With increasing of Sb5+ content, the electromechanical coupling factor (kp), piezoelectric constant (d33) and dielectric constant (ɛr) of the sintered specimens were increased up to y = 0.075, and then decreased. These results could be attributed to the shift of TO–T to near room temperature for Li0.04(K0.5Na0.5)0.96(Nb0.0925Sb0.075)O3.