Investigation of the electrical properties of textured 0.5[Ba(Zr_(0.2)Ti_(0.8))] O_3-0.5[(Ba_(0.7)Ca_(0.3))TiO_3] piezoceramics

摘要

In this study, lead-free 0.5[Ba(Zr_(0.2)Ti_(0.8))]O_3-0.5[(Ba_(0.7)Ca_(0.3))TiO_3] (BZT-BCT) piezoelectric ceramics were prepared in the temperature range of 1360-1480 ℃ by dry-pressing and tape-casting. 5 mole% plate-like BaTiO_3 templates were used for texturing BZT-BCT through templated grain growth process. Highly textured ceramics with up to 0.94° of grain orientation as determined by the Lotgering factor were obtained with optimum sintering conditions. Textured ceramics exhibited excellent electromechanical properties (d_(33)~* ＞ 900 pm/V, x ＞ 0.19%) and dielectric properties (ε_r ＞ 3000, tanδ ＜ 1.8%) at room temperature. The Curie-Weiss analysis indicated that while ceramics with randomly oriented grains showed a mixed character between normal and relaxor ferroelectric behavior, development of texture led to a decrease in the diffuseness of the phase transition.