Temperature dependence on the piezoelectric property of (1-x)(Na0.5K0.5)NbO3-xLiNbO3 ceramics

Lead-free (1-x)(Na0.5K0.5)NbO3-xLiNbO(3) ((1-x)NKN-xLN) piezoelectric cerarnics have been synthesized by solid state sintering between X = 0.040 and 0.080. The effects of temperature on the dielectric, ferroelectric and piezoelectric properties were investigated. For all the samples measured. the remanent polarization (P-r) and coercive field (E-c) showed a tendency of reduction with increasing temperature, but a planer-mode electromechanical coupling coefficient (k(p)) and frequency constant (N-p) varied in non-linearity as a function of temperature. The temperature dependence of the piezoelectric properties of (1 - x)NKN-xLN ceramics was strongly affected by the lithium content, too. The k(p) values enhanced at the tetra2onal-orthorhombic phase transition temperature for all the specimens with different Li contents due to the MPB effects. Especially for the x = 0.055 and 0.060 sample. the variation of elastic compliance also affected their piezoelectric property. (c) 2007 Elsevier Ltd. All rights reserved.