Ba_(0.5)Sr_(0.5)TiO_3薄膜、Ba_(0.1)Sr_(0.9)TiO_3/YBa_2Cu_3O_(7-δ)异质薄膜的制备及介电性能研究  

Preparation and dielectric properties of Ba0.5Sr0.5TiO3 thin films and Ba0.1Sr0.9TiO3/ YBa2Cu3O7-δ heterostructure films

作　　者：朱小红[1] 彭炜[1] 胡文斐[1] 陈莺飞[1] 郑东宁[1] 李林[1] 朱建国[2] 

机构地区：[1]中国科学院物理研究所超导国家重点实验室,北京100080 [2]四川大学材料科学与工程学院,四川成都610064

出　　处：《功能材料》2003年第2期179-183,共5页Journal of Functional Materials

基　　金：国家自然科学基金重点资助项目(59832050);清华大学新型陶瓷与精细工艺国家重点宴验室开放基金资助项目(KF0013)

摘　　要：铁电钛酸锶钡(BSTO)薄膜具备十分优越的铁电/介电性能,在可调谐微波器件和动态随机存储器(DRAM)方面显示出十分诱人的应用前景。而YBa2Cu3O7-δ(YBCO)高温超导薄膜作为其电极引入,明显降低了微波损耗,能够大大优化器件的性能。本文针对微波器件性能要求对比了各种常用基片的性能参数,描述了目前BSTO薄膜与BSTO/YBCO异质薄膜制备中存在的问题以及薄膜介电性能测试表征方法。利用脉冲激光沉积(PLD)技术成功制备出结构完整和质量较高的Ba0.5Sr0.5TiO3薄膜。同时,在1.2°斜切LaAlO3基片上研制有Ba0.1 Sr0.9TiO3/YBa2Cu3O7-δ异质双层膜,在1MHz频率、77K温度条件下,其介电常数为1200,介电损耗为0.0045,±30V直流偏压时可调性达到60％,在液氮温度下表现出良好的应用前景。Ferroelectric barium strontium titanate thin films possess excellent ferroelectric/ dielectric properties, and show very good application in passive microwave devices and dynamic random access memory. In addition, the microwave loss can be evidently decreased, and the various performances of the devices can be greatly optimized with YBCO high temperature superconducting thin films as bottom electrodes. In this pap.er, the parameters of regular substrates were compared according to application requirement of the microwave devices. Some techniques were described in order to obtain good properties of the Ba0.5 Sr0.5 TiO3 thin films and BSTO/YBCO heterostructures. The characterization of dielectric properties of thin films was also introduced in brief. Structurally perfect and high-quality Ba0.5Sr0.5TiO3 thin films were prepared successfully by PLD. What's more, Ba0. 1 Sr0.9 TiO3 / YBa2 Cu3O7 -δ bilayer het-erostructure was successfully developed on the 1. 2o vicinal LaAlOS substrate. The dielectric constant and loss tangent were 1200 and 0. 0045 respectively at 1MHz, and 77K. A tunability of 60% has been achieved under 30V DC bias, demonstrating their usefulness for frequency-agile microwave devices at the liquid nitrogen temperature.

关 键 词：异质结构 微波器件 高温超导 脉冲激光沉积 钛酸锶钡 铁电薄膜 

分 类 号：TM223[一般工业技术—材料科学与工程]