锶取代PZN-PMN-PT陶瓷的介电、压电性能研究

Effect of Sr Substitution on the Dielectric and Piezoelectric Properties of PZNPMNPT Ceramics

ＰＺＮＰＭＮＰＴ陶瓷在准同型相界具有良好的介电、压电性能．加入锶后，介电、压电性能有明显提高，居里点降低，同时三方相、四方相含量发生变化，使相界发生移动；在锶的摩尔分数为３％～５％时，压电性能最好．烧结后的样品经８５０℃退火处理后，样品的介电、压电性能均有大幅度提高，得到了压电系数ｄ３３高达６８０ｐＣ／Ｎ，ｄ３３达到－２８３ｐＣ／Ｎ，机电耦合系数ｋｐ达到５５％，ｋ３１达到３１％。

PZNPMNPT ceramics have good dielectric and piezoelectric properties near the morphotropic phase boundary (MPB). Enhancements of dielectric and piezoelectric properties become apparent after adding Sr: Curie temperature decreases and the phase boundary moves to the rhombohedral phase. The piezoelectric properties reach peak values when the mole content of Sr 2+ is 3% to 5%. The samples also show better dielectric and piezoelectric properties after thermally annealed at 850 ℃. In this work, d 33 =680 pC/N, d 31 =-280 pC/N, k p=48%, k 31 =31%, and dielectric constant ε m=25 000 are achieved.