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采用传统固相法制备了平均晶粒尺寸为5 μm的四方结构掺镧锆钛酸铅(PLZT)铁电陶瓷,在其表面涂银、切向预极化后刻蚀出刻槽,在刻槽表面压出维氏压痕并沿预极化方向施加外电场,利用Raman光谱原位观测了压痕裂纹尖端附近不同位置的畴变,分析了Raman软模E(2TO)和E(3TO+2LO)+B1峰的强度随观测点的变化规律.结果表明:在外电场作用下,裂纹尖端会发生电致应变和90°畴变;Raman谱和软模E(2TO)、E(3TO+2LO)+B1峰强度均会随着观测点距裂纹尖端距离的增大而减弱.

Lanthanum-doped lead zirconate titanate (PLZT) ferroelectric ceramics with average grain size of 5 mm and a tetragonal structure were prepared by the conventional solid state reaction method, and then were surface coated with silver and pre-polarized in tangential direction.Then a groove was etched in the silvered surface of the ceramics, sbsequently Vickers indentation was introduced on the groove surface and external electric field was applied along the pre-polarization direction.The domain switching at different positions near the indentation crack tips were in-situ observed by Raman spectroscopy.The variation of the peak intensity of Raman soft modes of E(2TO) and E(3TO+2LO)+B1 versus the observation point was analyzed.The results show that the electric induced strain and 90° domain switching occurred at crack tips under the external electric field.The peak intensity of Raman spectrum and soft modes of E(2TO) and E(3TO+2LO)+B1 decreased with the distance between observation point and crack tip increasing.