In-situ Raman observation on crack tips of Vickers indent in PLZT ceramics  

PLZT铁电陶瓷维氏压痕裂纹尖端的原位Raman观测(英文)

作　　者：张飒[1] 程璇[1] 张颍[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：《Transactions of Nonferrous Metals Society of China》2011年第10期2259-2263,共5页中国有色金属学报（英文版）

基　　金：Project(2006L2003)supported by the Fujian Key Laboratory of Advanced Materials,China;Project(10802070)supported by the National Natural Science Foundation of China

摘　　要：Vickers indentation was introduced into the originally in-plane and out-of-plane poled PLZT ceramics.The Raman spectra were in-situ recorded at selected crack tips before and after the indentations,as well as after the applications of external electric field.The results show that the changes in Raman intensities of optical modes could be sensitively related to 90° domain switching around the crack tips which are strongly dependent on the directions of original polarization and geometric locations.When the direction of electric field was perpendicular to the direction of original polarization,the 90° domain switching at crack tips of the Vickers indentation on the originally in-plane poled PLZT ceramics caused most significant change in the Raman intensity,which inhibited the crack growth.However,when the direction of electric field was parallel to the direction of original polarization,the growth of crack tips became predominantly without the 90° domain switching,which led to the crack growth.通过对预先切向极化和纵向极化的PLZT铁电陶瓷试样表面引入维氏压痕,在压痕引入前后以及外加电场作用下原位记录维氏压痕裂纹尖端处的Raman光谱变化。结果表明:裂纹尖端的Raman光学模的强度与90°畴变、试样的预先极化方向以及裂纹尖端的空间分布位置密切相关。当试样的极化方向与外加电场方向垂直时,极化试样的维氏压痕裂纹尖端发生90°畴变,抑制裂纹的生长,此时观测到的Raman光谱强度变化最显著。当试样的极化方向与外加电场方向平行时,几乎不发生90°畴变,将导致裂纹尖端的裂纹生长。

关 键 词：ferroelectric ceramics domain switching in-situ Raman spectroscopy Vickers indentation 

分 类 号：TQ174.1[化学工程—陶瓷工业]