Sol-Gel法硅基铁电薄膜研究

介绍了用溶胶 凝胶方法制备Pb(Zr0 .53Ti0 .4 7)O3(PZT)铁电薄膜的工艺流程。以硝酸锆、醋酸铅和钛酸四丁酯为原料 ,在 90 0℃ ,30min退火条件下制备了硅基PZT铁电薄膜。实验分析结果显示 ,PZT铁电薄膜的晶化很完善。研究了PZT铁电薄膜与硅之间的界面及其对铁电薄膜品质的影响。并在此基础上实现了制备PZT铁电薄膜的低温改进工艺。     

铁电薄膜退火方法的研究

以锆钛酸铅薄膜（PZT）为例，分析了国内外铁电薄膜退火的各种方法。针对解决铁电薄膜基底高温生长工艺与硅集成电路承受温度较低的不兼容及器件性质劣化的难题，分别对普通炉子退火、快速热退火及激光退火进行了详细的分析比较。激光低温退火技术有望成功地在未来应用PZT铁电薄膜制作组件时，增加其制备工艺设计的弹性和可行性。     

SOL-GEL方法制备PZT铁电薄膜新方法及铁电特性研究

我们用SOL-GEL方法对PZT的制备进行了深入细致的研究,PZT薄膜不同组分的加入顺序对铁电特性的影响较小,而精确地控制PZT铁电薄膜的组分是制备性能良好的铁电薄膜的关键,铁电薄膜的退火条件对铁电薄膜特性有着至关重要的影响.我们运用将Zr及Ti有机物溶液加入Pb的有机溶液的新的制备工艺流程以精确地控制Pb/Zr/Ti的组分,从而制备出性能良好的铁电薄膜.在大量实验的基础上,我们绘制出扩散炉和快速热退火时,钙钛矿的形成与退火温度及时间的关系图,并且得出PZT铁电薄膜最佳的退火温度和时间区域.     

不同组分PZT压电薄膜的性能

采用sol-gel工艺在Pt/Ti/SiO2/Si衬底上制备了不同条件的锆钛酸铅（PZT）薄膜.分析了不同的前烘温度、不同锆钛比例对PZT薄膜的微观结构和电特性所产生的影响.SEM分析结果显示,铁电薄膜的晶化较完善,薄膜表面均匀致密.用X射线衍射分析了不同条件制备的PZT薄膜,表明薄膜的微观结构和取向不仅对热处理的条件非常敏感,而且也深受薄膜组分的影响.铁电测试表明对PZT（锆/钛=30/70）,300℃热处理的薄膜具有最大的自发极化值.而对于不同锆钛比的薄膜,在准同型相界附近的53/47配比的PZT薄膜表现出最好的铁电性、介电性和最高的体电阻率.     

力电多场鼓包法测定PZT铁电薄膜的横向压电系数

为表征Pb(Zr_(0.52)Ti_(0.48))O_3(PZT)薄膜的横向压电性能,以纯力场鼓包测试模型和铁电薄膜材料压电方程为基础,推导了PZT铁电薄膜的力电耦合鼓包本构模型。采用溶胶-凝胶法制备了PZT铁电薄膜,并通过化学腐蚀法获得PZT薄膜鼓包样品。在外加电压为0~14V的条件下进行鼓包测试。结果表明,在纯力场作用下,PZT薄膜的弹性模量和残余应力分别为91.9GPa和36.2MPa;随着电压从2V变化到14V,PZT薄膜的横向压电系数d31从-28.9pm/V变化到-45.8pm/V。本工作所发展的力电耦合鼓包测试技术及力电耦合鼓包本构模型为评价铁电薄膜材料的横向压电性能提供了一种有效的分析方法。     

掺锡氧化铟基底上锆钛酸铅铁电薄膜的制备与表征

用溶胶-凝胶工艺在掺锡氧化铟导电氧化物基底上制备了锆钛酸铅（PZT）铁电薄膜．采用快速热处理工艺改进铁电薄膜的晶格取向,用X射线衍射仪分析了薄膜的结晶取向,分别基于Al／PZT／ITO,1TO／PZT／1TO电容结构利用Sawyer-Tower电路原理测试了薄膜的铁电性能．结果表明,在磁控溅射法生长的1TO表面能够制备出具有钙钛矿结构的（110）取向的PZT铁电薄膜,所得薄膜的相对介电常数达到1000,剩余极化强度Pr达到和Pt基底上接近的15．2uc／cm^2,矫顽场强Ec达到70．8kV/cm．并且利用TF Analyzer 2000铁电分析仪测试了PZT铁电薄膜的疲劳特性,发现ITO底电极上PZT薄膜经过108次反转后,剩余极化强度仅下降15％．研究表明：磁控溅射法制备的掺锡氧化铟透明导电薄膜ITO可以作为铁电薄膜的上下电极．     

Sol—Gel法硅基铁电薄膜研究

介绍了用溶胶－凝胶方法制备Ｐｂ（Ｚｒ０．５３Ｔｉ０．４７）Ｏ３（ＰＺＴ）铁电薄膜的工艺流程。以硝酸锆、醋酸铅和钛酸四丁酯为原料,在９００℃,３０ｍｉｎ退炎条件下制备了硅基ＰＺＴ铁电薄膜。实验分析结果显示,ＰＺＴ铁电薄膜的晶化很完善。研究了ＰＺＴ铁电薄膜与硅之间的界面及其对铁电薄膜品质的影响。并在此基础上实现了制备ＰＺＴ铁电薄膜的低温改进工艺。     

基于LaNiO_3和Pt电极的Pb(Zr_(0.52)Ti_(0.48))O_3薄膜制备和电学性能研究

采用了溶胶-凝胶(sol-gel)法分别在LaNiO3/Si和Pt/Ti/SiO2/Si基底上制备Pb(Zr0.52Ti0.48)O3(PZT)薄膜。X射线衍射(XRD)结果表明,在相同的工艺参数下PZT/LaNiO3薄膜表现出高度的(100)取向,而PZT/Pt薄膜则呈现(100)和(111)多晶混合取向。扫描电子显微镜(SEM)结果显示,PZT/LaNiO3薄膜表面晶粒尺寸更加均匀。经过铁电和介电性能测试,PZT/LaNiO3和PZT/Pt薄膜的剩余极化强度分别为24.4和15.3μC/cm2,矫顽场分别为130.90和243.23 kV/cm,介电常数分别为1 125和453。电场强度100 kV/cm时,漏电流分别为10-5和10-2数量级,同时铁电疲劳性能也明显改善。这些结果表明PZT/LaNiO3比PZT/Pt薄膜具有更好的电学性能,在铁电和介电器件方面具有良好的应用前景。     

LaNiO3缓冲层对Pb(Zr,Ti)O3铁电薄膜的影响

采用化学溶液法在Pt／Ti／SiO2／Si衬底上制备了PbZr0．4Ti0.6O3／LaNiO3(PZT／LNO)多层薄膜。X射线衍射测量表明LNO缓冲层的引入使PZT薄膜(111)择优取向度减小,(100)取向增加。原子力显微镜测量表明引入LNO缓冲层使得PZT薄膜表面更加平整、致密。在LNO缓冲层上制备的PZT薄膜具有优良的铁电特性和介电特性：LNO缓冲层厚度为40nm时,500kV／cm的外加电．场下。剩余极化(Pr)为37．6μC／cm^2,矫顽电场(Ec)为65kV／cm;100kHz时,介电常数达到822,并且发现LNO缓冲层的厚度为40nm,PZT的铁电、介电特性改进最为显著。     

激光脉冲外延生长Pb(Zr0.52Ti0.48)O3薄膜及其特性研究

利用激光脉冲法在LaAlO3衬底上沉积制备LaNiO3薄膜作为底电极并外延生长(100) Pb(Zr0.52Ti0.48)O3铁电薄膜,系统研究了生长温度对PZT外延结构和电学特性的影响.研究发现当生长温度高于550℃时即可得到外延(100)PZT薄膜.在对所制备的PZT薄膜的结构和性能测试表明,650℃下生长的PZT薄膜外延性最佳,并且表现出优异的介电和铁电性能,介电常数ε、剩余极化Pr和矫顽场Ec分别为900、26.5 μC/cm2和52.1kV/cm.试验还证实这种外延PZT薄膜具有优良的抗疲劳特性,可用于铁电存储器的制备中去.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...