TAN Hongen, ZHUANG Zhiqiang

(College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640)

Abstract: A-site and B-site ion-doped 0.67Pb(Mg_1/3Nb_2/3)O₃-0.33PbTiO₃ ceramics were prepared by an oxide solid state reactionmethod. Phase structure, dielectric and ferroelectric properties of the ceramics were studied. The investigation shows that: doping of A -site ions reduces the maximum dielectric constant, peak temperature of dielectric constant and remnant polarization of the ceramics. With the increasing of modifier content of B -site Mn^{2 +} , the content of pyrochlore phase decreases and the piezoelectric properties get hardened with the increase of Mn composition. Dielectric constant,piezoelectric constant d₃₃ and electro -mechanical quality factor Qm increase, but dielectric loss tanδ decreases with Mn composition when Mn composition is less than 1.5mol%.ε, K_p, Q_m, tanδ and d₃₃ of the ceramic doped with 1.5mol% Mn are 2300, 0.54, 900, 0.004 and 400pC/N respectively. The ceramic could be used for the application of high power piezoelectric transformer.

Key words: piezoelectric ceramic, PMN-PT, phase structure, dielectric, ferroelectric, substitution