PLZT铁电陶瓷裂纹尖端附近畴变的原位Raman观测  

In-situ Raman Observation of Domain Switching near Crack Tip in PLZT Ferroelectric Ceramics

作　　者：张飒[1] 

机构地区：[1]厦门大学材料学院,福建省特种先进材料重点实验室,厦门361005

出　　处：《机械工程材料》2017年第6期20-24,共5页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51302236);福建省自然科学基金资助项目(2014J01205)

摘　　要：采用传统固相法制备了平均晶粒尺寸为5μm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（3TOq-2LO）q-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） q-B1 decreased with the distance between observation point and crack tip increasing.

关 键 词：PLZT铁电陶瓷 原位Raman观测 畴变 裂纹尖端 

分 类 号：TB321[一般工业技术—材料科学与工程]