The effect of composition on microstructure and properties of PNW-PMS-PZT ceramics for high-power piezoelectric transformer

(Pb0.95Sr0.05)[(Mn1/3Sb2/3),(Ni1/2W1/2)(y)(Zr1/2Ti1/2)(z)]O-3 piezoelectric ceramics (abbreviated as PNW-PMS-PZT) with 1 mol% excess PbO, 0.25 wt% CeO2 and 0.2 wt% MnO2 were synthesized by traditional ceramics process. The effect of Pb(Mn1/3Sb2/3)O-3 (abbreviated as PMS) and Pb(Ni1/2W1/2)O-3 (abbreviated as PNW) on phase structure, dielectric and piezoelectric properties was investigated in detail. The content of perovskite phase of all ceramics specimens is 100%, the phase structure of PNW-PMS-PZT ceramics changed from tetragonal phase to single rhombohedral phase with the amount of PMS and PNW increased. Take into consideration dielectric constant, epsilon(r), dielectric loss tan delta, electromechanical coupling factor k(p), mechanical quality factor Q(m), Curie temperature T-c and sintering temperature, it was concluded that the ceramics with composition of x = 0.06, y = 0.02, z = 0.92 can be used for high-power piezoelectric transformer. These properties include epsilon(r) = 2138, tan delta = 0.0058, k(p) = 0.613, Q(m) = 1275, d(33) = 380 pC/N, T-c = 205 degreesC. (C) 2004 Published by Elsevier B.V.