Dielectric and Piezoelectric Properties of [Li 0.04 (Na 0.54 K 0.46 ) 0.96 ] (Nb 0.84 Ta 0.10 Sb 0.06 )O 3 Lead-Free Ceramics as a Function of (Bi,Na)TiO 3 Substitution.

In order to develop lead-free composition ceramics for piezoelectric actuator, sensor, and transformer applications, (1-x)[Li0.04(Na0.54K0.46)]0.96(Nb0.84Ta0.10Sb0.06)O3 + x(Bi0.5Na0.5)TiO3 (x = 0∼2 mol%) composition ceramics were fabricated by a conventional sintering technique. The influences of (Bi0.5Na0.5)TiO3(abbreviated as BNT) on the microstructure, the dielectric, ferroelectric and piezoelectric properties of the ceramics were investigated. The crystal structure of specimens with x = 0 mol% exhibited an orthorhombic structure. However, at the compositions more than 0.5 mol%, the crystal structure showed tetragonal structure. The temperature dependence of dielectric constant showed that Curie temperature decreased with the increase of BNT substitution content. At room temperature, the ceramics substituted with 1 mol% BNT had a piezoelectric constant d33 = 222.6 pC/N, electromechanical coupling factor kp = 0.36, mechanical quality factor Qm = 78 and dielectric constant ϵr = 1570, respectively. [ABSTRACT FROM PUBLISHER]