纳米PZT粉体制备及PZT/水泥基复合材料压电性能

采用溶胶-凝胶法,结合正交试验设计,研究了不同反应条件((CH3COO)2Pb浓度、pH值、反应时间和煅烧温度)对PZT粉体结晶程度和晶粒大小的影响。用压制成型法制备出PZT压电陶瓷和PZT/硫铝酸盐水泥基复合材料。用正交极差与方差法分析了反应条件对PZT粉体物相与粒度及陶瓷片和复合材料的压电与介电性能的影响,得出粉体最佳制备工艺。结果显示:最佳反应条件为(CH3COO)2Pb浓度为15%,pH=5.0,反应时间2h,煅烧温度600℃;煅烧温度对陶瓷片及复合材料的压电与介电性能影响最显著;相应陶瓷片压电常数d33、相对介电常数εr分别为38.5pC/N、1.3;而复合材料的d33、εr分别为4.4pC/N、29.4,数值偏低可能是水泥水化不充分,结构不致密所致。     

制粉工艺对BaTiO3粉体理化性能的影响

本文用化学共沉淀法制备BaTiO3超细粉,实验中分别采用氢氧化钠和草酸作沉淀剂。实验发现,采用不同的沉淀剂均能制出具有四方晶相的BaTiO3粉体,但其所含微量成分有所不同,粉体粒度分布有较大差别。通过对粉体进行半导化处理,发现用氢氧化钠作沉淀剂时不易半导化,且其烧结性能及机械性能较差,而用草酸作沉淀剂所得的粉体易半导化,且具有较好的烧结性能和机械性能。     

Sol Gel法制备PZT粉体的工艺研究

以丙醇锆(C12H28O4Zr)、醋酸铅(Pb(CH3COO)2.3H2O)、异丙醇钛(Ti{OCH(CH3)2}4)为原料,采用改进的溶胶-凝胶(Sol-Gel)工艺,研究了不同的热处理制度对于Pb(Zr0.52Ti0.48)O3粉体的物相形成、晶粒尺寸及颗粒分散度等的影响。实验结果表明,Sol-Gel法制备PZT粉体,预结晶温度段,改变烧结时间,对于粉体颗粒的尺寸影响不大;结晶温度段,改变结晶时间或结晶温度,会对颗粒尺寸产生较大的影响。     

制粉工艺对BaTiO_3粉体理化性能的影响

本文用化学共沉淀法制备 Ba Ti O3超细粉 ,实验中分别采用氢氧化钠和草酸作沉淀剂。实验发现 ,采用不同的沉淀剂均能制出具有四方晶相的 Ba Ti O3粉体 ,但其所含微量成分有所不同 ,粉体粒度分布有较大差别。通过对粉体进行半导化处理 ,发现用氢氧化钠作沉淀剂时不易半导化 ,且其烧结性能及机械性能较差 ,而用草酸作沉淀剂所得的粉体易半导化 ,且具有较好的烧结性能和机械性能。     

共沉淀法制备PDP用红色荧光粉(Y, Gd)BO3:Eu3+的正交实验研究

以Y2O3,Gd2O3,Eu2O3和硼酸为原料,草酸为沉淀剂,采用共沉淀法合成了PDP用红色荧光粉(Y, Gd)BO3:Eu3+.同时,利用正交实验探讨了合成工艺条件对荧光粉相对发光强度的影响.实验确定了制备PDP用红色荧光粉(Y, Gd)BO3:Eu3+的优化工艺条件:沉淀剂/金属离子总量为1.2:1;pH=8;离子混合超声20 min;沉淀超声1 h;650 ℃预烧1 h;950 ℃烧结2 h.采用PDP真空紫外测试系统、X射线衍射仪、环境扫描电镜对荧光粉进行了表征.结果表明:在优化工艺条件下所制备的荧光粉为六方晶系,空间群为P63/m ,平均粒径约为300 nm.     

共沉淀法制备PZT粉体及性能研究

采用共沉淀法,利用Pb(Ac)2.3H2O、ZrOCl2.8H2O、TiCl4为原料,以浓氨水为沉淀剂,聚乙二醇(PEG)为表面活性剂,正丁醇为助溶剂。经实验确定的最佳工艺条件是:反应物浓度为1 mol/L,反应物配比为r[Pb(Ac)2]:r[ZrOCl2]:r[TiCl4]:r[NH3.H2O]=2:1.04:1:12,盐酸浓度为0.04~0.08 mol/L,PEG浓度为0.004~0.006 mol/L,反应温度为常温,反应时间为1~2 h。能够制备出粒度均匀、分散性好的纳米PZT超细粉体,粒径为10~30 nm。650℃煅烧保温2 h,已完全合成为单一晶型钙钛矿PZT固溶体。1 150℃烧结保温2 h,然后对此压电陶瓷的相对介电常数3Tε3/0ε、介电损耗tanδ、压电应变常数d33、机电耦合系数kp、机械品质因数Qm、体积密度ρ、居里温度TC等主要性能进行了测试;对显微结构及相组成进行了分析,实验数据表明可得到一种综合性能优良的压电材料。     

应用于FRAM的集成铁电电容的研究

集成铁电电容的制备是铁电存储器的关键工艺之一。该文采用射频(RF)磁控溅射法在Pt/Ti/SiO2/Si制备Pb(Zr,Ti)O3(PZT)薄膜,上下电极Pt采用剥离技术工艺制备,刻蚀PZT薄膜,形成Pt/PZT/Pt/Ti/SiO2/Si集成电容结构,最后高温快速退火。结果表明,这种工艺条件可制备性能良好的铁电电容,符合铁电存储器对铁电电容的要求。     

Ce：YIG粉体的制备及性能研究

本实验采用共沉淀法制备Ce:YIG粉体。通过对反应体系的pH值的研究，确定了反应的最佳pH值范围为8－9，得到了颗粒分布均匀的粉体。经电子探针微区分析，粉体的组分与实验设计的配方相吻合。粉体在不同的温度条件下进行烧结实验，经XRD分析证实，YIG的成相温度在650℃附近。可以认为，用共沉淀法制备的Ce:YIG粉体化学活性好，烧结温度低。     

一种制备纳米Fe3O4的新方法及其磁性能研究

在正丙醇–水体系中,以NaOH为沉淀剂,用共沉淀法制备了纳米Fe3O4粒子,并用TEM和XRD对其进行了表征。考察了制备过程中工艺参数对Fe3O4颗粒大小的影响,并对影响机理进行了探讨。结果表明:纳米Fe3O4的平均粒径约为15nm;其饱和磁化强度可达73.34Am2/kg,比用水热法(42Am2/kg)和共沉淀法(60Am2/kg)制备的Fe3O4纳米粒子的要高。     

采用金属有机化合物热分解法研制锆钛酸铅薄膜

详细研究了采用金属有机化合物热分解法制备锆钛酸铅Pb（Zr0.53Ti0.47）O3铁电薄膜的工艺,讨论了影响PZT薄膜相结构的因素。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.