(111)取向(Pb,La)TiO_3铁电薄膜中90°纳米带状畴与热释电性能的研究  

Study of nanoscale banded 90° domain patterns and pyroelectric properties in(111)oriented(Pb,La)TiO_3 thin films

作　　者：刘洪[1] 蒲朝辉[1] 龚小刚[1] 王志红[2] 黄惠东[2] 李言荣[2] 肖定全[1] 朱建国[1] 

机构地区：[1]四川大学材料科学与工程学院,成都610064 [2]电子科技大学微电子与固体电子学院,成都610054

出　　处：《物理学报》2006年第11期6123-6128,共6页Acta Physica Sinica

基　　金：国家自然科学重点基金(批准号:50132020);国家自然科学基金(批准号:60471044);国家安全重大基础研究计划(批准号:Z06-1)资助的课题.~~

摘　　要：采用射频磁控溅射技术在Pt/Ti/SiO2/Si(100)衬底上生长了掺镧钛酸铅(PLT)铁电薄膜.用X射线衍射技术(XRD)研究了PLT薄膜结晶性能,结果表明PLT薄膜为(111)择优取向钙钛矿相织构.使用原子力显微镜(AFM)和压电响应力显微镜(PFM)分别观察了PLT薄膜的表面形貌和对应区域的电畴结构.PFM观察显示PLT薄膜中存在90°纳米带状畴,电畴的极化为首尾相接的低能量的排列方式,带状畴的宽度为20—60nm.研究了PLT10铁电薄膜的制备条件与性能之间的关系.发现在优化条件下制备的PLT10铁电薄膜的介电常数εr为365、介电损耗tgδ为0.02,热释电系数γ为2.18×10-8C.(cm2.K)-1,可以满足制备非制冷红外探测器的需要.Lanthanum doped lead titanate （PET） ferroeleetric thin films were grown on Pt/Ti/SiO2/Si （100） substrates using RF magnetron sputtering. X-ray Diffraction （XRD） was applied to study crystalline properties of PLT films, and XRD patterns of PET thin films show that there appeared （ 111 ） preferred-oriented tetragonal perovskite phase. The ferroelectric domain patterns and the corresponding topography of PLT thin films have been investigated using piezoresponse force microscopy （PFM） and atomic force microscopy （AFM）, respectively. PFM observations show that there exist nanoscale banded 90° domain patterns 20 to 60 nm in width and low energy head-to-tail polarization configurations in PLT film. The relationship between fabricating conditions and properties of PLT10 thin films was studied, It was found that PLT10 thin film fabricated under the optimized conditions possess dielectric constant εr = 365, dielectric loss tgδ = 0.02, and pyroelectric coefficient γ = 2.18 ×10^-3 C· （cm^2· K）^ -1, respectively. The PLT thin films could meet the needs for uncooled pyroelectric infrared sensors.

关 键 词：PLT薄膜 电畴 PFM 极化 

分 类 号：O484.42[理学—固体物理]