锆钛酸铅镧陶瓷裂尖处由电场诱发90°铁电畴变的实验研究  

EXPERIMENTAL STUDY ON 90 DOMAIN SWITCHING AT THE CRACK TIP OF TETRAGONAL LANTHANUM_MODIFIED LEAD ZIRCONATE TITANATE INDUCED BY AN ELECTRIC FIELD

作　　者：方菲[1] 杨卫[1] 朱廷 

机构地区：[1]清华大学工程力学系

出　　处：《硅酸盐学报》1999年第3期310-315,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金

摘　　要：用传统陶瓷工艺合成制备了（Ｐｂ０．９６Ｌａ０．０４）（Ｚｒ０．４０Ｔｉ０．６０）０．９９Ｏ３（ＰＬＺＴ）铁电陶瓷，并用Ｘ射线衍射对其结构进行了测定，表明室温下ＰＬＺＴ陶瓷为铁电四方相结构：ａ＝ｂ＝０．４０５５ｎｍ，ｃ＝０．４１０９ｎｍ，ｃ／ａ＝１．０１３．将ＰＬＺＴ陶瓷极化后，在抛光面进行压力为４９Ｎ的Ｖｉｃｋｅｒｓ压痕，并施加强度为０．４Ｅｃ，０．５Ｅｃ，０．６Ｅｃ（Ｅｃ＝１１００Ｖ／ｍｍ）的侧向电场．用场发射扫描电镜研究观察ＰＬＺＴ试样极化前、极化后以及在侧向电场作用下压痕裂纹附近铁电畴结构的形态及其变化．结果表明在０．６Ｅｃ的侧向电场作用下，压痕裂纹附近发生了９０°铁电畴变，在扫描电镜的铁电畴结构形貌图上再次出现了平直的９０°铁电畴界．探讨了９０°铁电畴变的形成及促发机制．Lanthanum modified lead zirconate titanate ferroelectric ceramics, (Pb0.96La0.04)(Zr0.40Ti0.60)0.99O3 was synthesized by the conventional powder processing technique. XRD results reveal that the samples belong to the tetragonal phase with a=b=0.405 5 nm, c=0.410 9 nm, c/a=1.013. After polariation, the samples were indented by a 49 N Vickers indenter, and lateral electric fields of 0.4Ec, 0.5Ec,0.6Ec(Ec=1 100 V/mm) were applied respectively. Field emission scanning electron microscopy shows that 90 domain switching appears near the tip of the indentation-crack induced by a lateral electric field of 0.6Ec. A formation mechanism of the 90 domain switching is discussed.

关 键 词：锆钛酸铅镧陶瓷 铁电畴 微结构 铁电陶瓷 电场 

分 类 号：TQ174.13[化学工程—陶瓷工业] TQ174.756[化学工程—硅酸盐工业]