掺镧钛酸铅铁电薄膜的电畴与热释电性能研究

采用射频磁控溅射技术在Pt/Ti/SiO2/Si(100)基底上生长了掺镧钛酸铅[(Pb0.9La0.1)TiO3, PLT10]铁电薄膜.用X射线衍射研究了PLT10薄膜的结晶相结构.分别使用原子力显微镜和压电响应力显微镜观察了PLT10铁电薄膜的表面形貌和对应区域的电畴结构.测试了PLT10铁电薄膜的电学参数,研究了PLT10铁电薄膜的制备条件与其性能之间的关系.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2.20×10-8C·(cm2·K)-1,可以满足制备非制冷红外探测器的需要.     

PLT测井在苏丹穆格莱德油田的应用

苏丹穆格莱德油田是中石油和其它国家的一些石油公司与苏丹政府合作开发的油田,目前已经合作开发了近10年,油田开发进入到中期。在油田开发的初期就开始了生产测井的动态监测,到目前为止已经进行了几十口井的生产测井任务,取得了较好的应用效果。尤其开始注水开采工艺以后,很多产出井的含水迅速上升,对产出井的找水,对注水井注水效果的检验,使生产测井的作用愈加显现。受条件限制,目前主要开展的动态监测测井项目是PLT测井。PLT测井在国外的高排量井中应用效果显著,对产液、注入层的动态监测、问题井原因的探寻,对油藏动用情况的分析和工程井问题的解决起到了举足轻重的作用。本文对PLT测井在穆格莱德油田开发中的应用实例加以分析,对其重要的应用价值予以展示,并对该油田今后的动态检测测井发展趋势进行了分析和预测。     

循环间歇溅射工艺对PLT薄膜性能的影响

采用射频磁控溅射技术利用循环间歇溅射工艺,在Pt/Ti/SiO2/Si基片上制备出了镧钛酸铅(PLT)薄膜。通过原子力显微镜、X-射线衍射仪分析了循环间歇溅射工艺对薄膜形貌、结构和铁电性能的影响。实验结果表明,相比于连续溅射工艺,循环间歇溅射工艺的基片温度较低,且制得的PLT薄膜晶粒细小、均匀,结构致密。薄膜具有纯钙钛矿型结构,循环次数从1次增加到3次,其(100)和(200)峰衍射强度逐渐增强,结晶性提高,铁电性能逐渐增强,其饱和极化强度由28μC/cm2增大到53μC/cm2,剩余极化强度由5μC/cm2增大到12μC/cm2。循环4次溅射后,薄膜的结晶性和铁电性开始下降。     

纳米晶粒PLT（28）薄膜的制备和性能研究

本文首先报道了纳米晶粒ＰＬＴ（２８）薄膜的制备，并研究其微结构、铁电、电光性能，讨论不同热处理条件对薄膜微结构的影响，以及晶粒尺寸与电光性能的关系。     

Preparation of (Pb0.88La0.12)TiO3 thin films for dynamic random access memory by low pressure-metalorganic chemical vapor deposition

La-modified lead titanate (PLT) thin films were prepared by hot-wall type low pressure-metalorganic chemical vapor deposition method. Pb(dpm)₂, La(dpm)₃, and titanium tetraisopropoxide were used as source materials. The films were deposited at 500°C under the low pressure of 1000 mTorr and then annealed at 650°C for 10 min in oxygen ambient. Sputter-deposited platinum electrodes and 180 nm thick PLT thin films were employed to form MIM capacitors with the best combination of high charge storage density (26.7 μC/cm² at 3V) and low leakage current density (1.5 × 10^-7 A/cm² at 3V). The measured dielectric constant and dielectric loss were 1000∼1200 and 0.06∼0.07 at zero bias and 100 kHz, respectively.     

纳米晶PLT薄膜的合成与表征

纳木材料的制备技术结合Ｓｏｌ－Ｇｅｌ工艺在（１００）单晶硅上制备了粒径在２０～８０ｎｍ的多晶ＰＬＴ（Ｐｂ＿（１－ｘ）Ｌａ＿ｘＴｉＯ＿３）纳采晶膜，并用ＩＲ、ＴＧＡ、ＸＲＤ、ＳＥＭ等对膜的制备过程及结果进行了研究。结果表明，所制各的ＰＬＴ纳米晶膜属多晶钙钦矿结构，薄膜表面平整致密，厚度均匀，约为１μ，颗粒为球形或椭球形，粒度呈对称分布。     

微电脑控制的血细胞计数仪

本文介绍了以ＨＤ６４１８０单片机为核心的血细胞计数仪的测量原理、硬件及软件实现。     

基于矢量图形的G代码自动生成软件路径优化算法的研究

分析矢量图形的数据格式,并对矢量图形有效数据提取及G代码自动生成软件的路径优化算法进行研究。实践证明,该算法切实可行。     

Deposition of large-area graded (Pb1−xLax)TiO3 thin films by pulsed laser depesition

Abstract

Thin films of the composition (Pb_1?xLa_x)TiO₃, PLT, with x=0.05, 0.10 and 0.15 were sequentially pulsed laser deposited on Pt(Si) substrates at 200°C, followed by post-annealing at 550–600°C in furnace to result in a film with graded composition. The ferroelectric properties of the graded materials are markedly different from those of the uniform thin PLT films. For down graded materials, which contain PLT5 composition (x=0.05) at the top and PLT 15 composition (x=0.15) at the bottom of the films, the hysteresis loops are slim and the width of the P-E curves increases with voltage cycling, attaining an equilibrium polarization states similar to the P-E properties of PLT 15 thin films. By contrast, the ferroelectric hysteresis properties reaches the same value as those of PLT5 thin films when the composition is up-graded.     

Electrical properties of paraelectric PLT(28) thin films deposited by dc magnetron sputtering

Abstract

Paraelectric [Pb, La]TiO₃ (PLT, La = 28 mol%) thin films were prepared by dc magnetron sputtering using a multi-element metal target. In order to crystallize the as-deposited PLT thin films into the cubic perovskite structure, a heat treatment was applied at annealing temperatures ranging between 450 and 750°C. The electrical measurements such as dielectric properties, polarization-electric field (P-E), and current-voltage (I–V) were investigated with the change of annealing temperature. The dielectric constant and dissipation factor of paraelectric PLT film annealed at 750°C were 1216 and 0.018, respectively. The charge storage density was approximately 12.5 μC/cm². The leakage current density in PLT film annealed at 650°C was around 0.1 μA/cm² at the electric field of 0.25 MV/cm.