薄膜厚度对PZT/STO铁电电容器隧穿电阻的影响  

Effects of film thickness on the tunneling electroresistance of PZT/STO ferroelectric capacitors

作　　者：王英龙[1] 刘林[1] 张鹏程[1] 梁伟华[1] 丁学成[1] 褚立志[1] 邓泽超[1] 

机构地区：[1]河北大学物理科学与技术学院,河北保定071002

出　　处：《功能材料》2013年第3期363-366,370,共5页Journal of Functional Materials

基　　金：国家重点基础研究发展计划(973计划)资助项目(2011CB612305);河北省自然科学基金资助项目(E2011201134;E2012201035)

摘　　要：结合Landau-Devonshire自由能理论和晶格模型,研究了PbZr1-xTixO3(PZT)/SrTiO3(STO)复合薄膜中PZT和STO厚度对铁电隧道结极化强度、电导和隧穿电阻等的影响。模拟结果表明,随着层数增加,极化强度增大;平均极化强度随着PZT厚度增加而增强,随着STO厚度增加而减弱;随着PZT和STO厚度增加,电导减小,隧穿电阻率增加;当厚度变化相同时,PZT引起电导的变化大,隧穿电阻率变化小。考虑薄膜面积的影响,当薄膜面积从无限大变成有限大时,极化强度、电导和隧穿电阻均减小。Combining Landau-Devonshire free energy theory and lattice model,the effects of the thickness of PZT and STO in the PbZr1-xTixO3（PZT）/SrTiO3（STO） composite films on the intensity of polarization,conductance and tunneling electroresistance in the ferroelectric tunnel junction have been discussed.The results show that as the number of layers increases,the intensity of polarization increases.And average polarization strength increases with the increasing PZT thickness,but it decreases with increasing STO thickness.Conductance decrease and tunneling electroresistance increases with the increasing PZT and STO thickness.When the change of film thickness is the same,PZT cause a bigger change of conductance,yet a less change of tunneling electroresistance.Considering the effects of film area,intensity of polarization,conductance and tunneling electroresistance decrease when the film area changes from infinity into finite.

关 键 词：铁电电容器 隧穿效应 Landau模型 PZT 

分 类 号：O469[理学—凝聚态物理]