La_(0.5)Sr_(0.5)CoO_3/Pb(Zr_(0.4)Ti_(0.6))O_3/La_(0.5)Sr_(0.5)CoO_3铁电电容器的结构和性能研究  

Structure and Properties of La_(0.5)Sr_(0.5)CoO_3/Pb(Zr_(0.4)Ti_(0.6))O_3/La_(0.5)Sr_(0.5)CoO_3 Ferroelectric Capacitor

作　　者：陈江恩[1,2] 刘保亭[1] 孙杰[1,2] 郭延岭[2] 马蕾[2] 娄建忠[2] 彭英才[2] 

机构地区：[1]河北大学物理科学与技术学院,保定071002 [2]河北大学电子信息工程学院,保定071002

出　　处：《人工晶体学报》2010年第2期350-354,364,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.60876055);河北省自然科学基金项目(E2008000620;E2009000207);教育部科学技术研究重点项目(No.207013);河北省应用基础研究计划重点基础研究项目(No.08965124D)

摘　　要：采用磁控溅射法和脉冲激光沉积法,在SrTiO3(001)衬底上制备了La0.5Sr0.5CoO3(70 nm)/Pb(Zr0.4Ti0.6)O3(70 nm)/La0.5Sr0.5CoO3(70 nm)(LSCO/PZT/LSCO)铁电电容器异质结。X射线衍射结果表明:LSCO和PZT薄膜均为外延结构。在5 V的外加电压下,LSCO/PZT/LSCO电容器具有较低的矫顽电压(0.49 V),较高的剩余极化强度(41.7μC/cm2)和较低的漏电流密度(1.97×10-5A/cm2),LSCO/PZT/LSCO电容器的最大介电常数为1073。漏电流的分析表明:当外加电压小于0.6 V时,电容器满足欧姆导电机制;当外加电压大于0.6 V时,符合空间电荷限制电流(SCLC)导电机制。La0.5Sr0.5CoO3（70 nm）/Pb（Zr0.4Ti0.6）O3（70 nm）/La0.5Sr0.5CoO3（70 nm）（LSCO/PZT/LSCO） capacitor was fabricated on SrTiO3（001） substrate by RF magnetron sputtering and pulsed laser deposition（PLD） method.X-ray diffraction（XRD） shows that both LSCO and PZT thin films are epitaxial structures.It is found that the coercive voltage,remnant polarization,leakage current density and the maximum dielectric constant of LSCO/PZT/LSCO capacitor measured at the voltage of 5 V are 0.49 V,41.7 μC/cm^2,1.97×10^-5 A/cm^2,1073,respectively.Leakage current density of the LSCO/PZT/LSCO capacitor is further investigated,which meets ohmic behavior at lower voltage（〈0.6 V） and agrees well with the space-charge-limited current（SCLC） theory at higher voltage（〉0.6 V）.

关 键 词：铁电电容器 PZT 外延薄膜 导电机制 

分 类 号：TM223[一般工业技术—材料科学与工程]