0.96(Na0.5K0.5)NbO3-0.04(Ba(1-x)Srx)TiO3 무연 세라믹스의 유전 및 압전 특성

Abstract

0.96(Na0.5K0.5)NbO3-0.04(Ba(1-x)Srx)TiO3 lead free piezoelectric ceramics were synthesized to enhance the piezoelectric properties of (Na,K)NbO3. The systhesis and sintering method were the conventional solid state reaction method and general sintering method in air atmosphere. The polymorphic phase transition(PPT) was observed at all composition(0 ≤ x ≤ 0.05) when (Ba(1-x)Srx)TiO3 were added in the (Na0.5K0.5)NbO3. As Sr concentration was increased, grain size, dielectric loss(tanδ) and mechanical quality factor(Qm) were decreased and piezoelectric constant(d33) and electromechanical coupling factor(kp) were increased within a limited value. The optimized piezoelectric and properties, d33, kp, Qm, and tand, of 0.96(Na0.5K0.5)NbO3-0.04(Ba(1-x)Srx)TiO3 were 139 pC/N, 0.31 %, 95, 0.04 at the composition of x=0.04.