SiC纤维补强微晶玻璃基复合材料的界面结合

本文通过ＳｉＣ纤维对ＬＣＡＳ（Ｌｉ２Ｏ－ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２）和ＭＡＳ（ＭｇＯ－Ａｌ２Ｏ３－ＳｉＯ２）微晶玻璃的补强，观察和分析了在不同复合系统中纤维与基体的界面结合。在ＳｉＣ纤维／ＬＣＡＳ微晶玻璃复合系统中，发现纤维与基体之间有一中间界面层，它主要是在复合材料的烧结过程中通过扩散形成，并且于１２００℃时在界面上形成富Ｃ层。ＳｉＣ纤维／ＭＡＳ微晶玻璃基复合材料由于在烧结过程中有化学反应发生     

(YCa)F3助烧AlN陶瓷的显微结构和热导率

采用（ＣａＹ）Ｆ_３为助烧结剂，低温烧结（１６５０℃， ６ｈ）制备出热导率为２０８Ｗ／ｍ·Ｋ的ＡＩＮ陶瓷，在烧结过程中，热导率随保温时间的变化服从方程：λ（ｔ）＝λ∞－△λ（０）·ｅ~（－ｔ／ｒ）·用ＳＥＭ、 ＳＴｈＭ、 ＴＥＭ和 ＨＲＥＭ对 ＡＩＮ陶瓷的显微结构及其对热导率的影响进行了研究，结果表明，晶粒尺寸对ＡＩＮ陶瓷热导率的影响可以忽略，而分隔在ＡＩＮ晶粒之间的晶界相会降低热导率。     

GdSe涂层(CdSe/Ni)的烧结工艺对半导体隔膜电极(SnO_2·P/CdSe/Ni)性能的影响

通过Ｘ射线衍射（ＸＲＤ）、扫描电子显微镜（ＳＥＭ）、透射电子显微镜（ＴＥＭ）和高能电子衍射（ＲＨＥＥＤ）等技术，研究了由蒸发冷凝法制备的ｎ型半导体材料ＧｄＳｅ超细微粒涂层（ＣｄＳｅ／Ｎｉ）的烧结工艺。实验指出，烧结后的ＧｄＳｅ粉体涂层的结晶形态、膜层的致密均匀性以及结晶粒度的尺寸等均与烧结的工艺条件密切相关。将涂在Ｎｉ箔上的ＧｄＳｅ粉体膜层置于氩气氛中，在缓慢升降温的条件下，于４５０～５００℃温度下恒温２ｈ的多次重复烧结，可以获得表面平整致密、在衬底Ｎｉ箔上附着力强的ＧｄＳｅ多晶膜层，以下称ＣｄＳｅ／Ｎｉ为烧结体。将烧结体应用于半导体隔膜电极（（ＳｎＯ２·Ｐ／ＣｄＳｅ／Ｎｉ）中，可有效地改善半导体隔膜电化学伏打电池（ＳＣ－ＳＥＰ电池）的光电化学特性。     

(YCa)F3助烧AIN陶瓷的显微结构和热导率

采用（ＣａＹ）Ｆ３为助烧结剂,低温烧结（１６５０℃,６ｈ）制备出热导率为２０８Ｗ／ｍＫ的ＡＩＮ陶瓷,在烧结过程中,热导率随保温时间的变化服从方程,λ（ｔ）＝λ∞－△λ（．３＾－６／ｒ,用ＳＥＭ、ＳＴｈＭ、ＴＥＭ和ＨＲＥＭ对ＡＩＮ陶瓷的显微结构及其对热导率的影响进行了研究。结果表明,晶粒尺２对ＡＩＮ陶瓷热导率的影响可以忽略,而分隔在ＡＮＩ晶粒之间的昌界相会降低热导率。     

等离子喷涂陶瓷涂层透射电镜样品的制备方法

介绍了在４５＃碳钢上等离子喷涂ＮｉＣｒＡｌ粘结层与Ａｌ２Ｏ３＋１３ｗｔ％ＴｉＯ２陶瓷涂层界面研究的ＴＥＭ样品制备方法。ＳＥＭ和ＴＥＭ初步研究结果表明，陶瓷呈层状结构，片层间除存在完全接触区外，同时存在非接触区、金属粘结层－陶瓷涂层界面具有一定的厚度。     

AlN-W多层共烧结基片的界面分析

本文利用光学显微镜和扫描电镜对共烧结多层ＡｌＮ－Ｗ界面特征进行了观察与研究。光学显微镜观察表明：Ａｌ－Ｗ共烧界面为起伏交错的交联状，ＡｌＮ和Ｗ各自嵌入到对方基体中。ＳＥＭ进一步观察表明，内交联的界面实现了Ｗ层在ＡｌＮ基体上的附着。界面处无明显的次生相生成。ＳＥＭ的能谱（ＥＤＡＸ）对界面上的Ａｌ和Ｗ元素分布进行表明：在几微米的分辨率范围内，既没有Ｗ向ＡｌＮ层的扩散，也没有Ａｌ向Ｗ层的扩散。通过对剥离Ｗ膜界面侧Ｗ形貌与自由表面Ｗ形貌对比观察表明，共烧界面Ｗ的重结晶与晶粒长大受到ＡｌＮ的制约，晶粒呈小晶粒结构。     

SiC／Al合金层状复合材料的机械性能及损伤行为

在室温条件下测定了Ａｌ合金以连续层状形式存在于ＳｉＣ陶瓷层间并渗透入ＳｉＣ陶瓷层内、Ａｌ合金浓度呈层状变化高低相间，以及Ａｌ合金和ＳｉＣ陶瓷均匀分布相互渗透三种ＳｉＣ含量相同而结构形式不同的ＳｉＣ／Ａｌ合金复合材料的机械性能；用ＳＥＭ和光学显微镜观察分析了复合材料的断口形貌及裂纹扩展过程。结果表明，在ＳｉＣ陶瓷层间以连续层状形式存在的Ａｌ合金在应力作用下发生较大程度的塑性变形，在裂纹尾部被拉伸和形成桥接，引起能量耗散，减缓裂纹扩展速度，防止裂纹张开，使复合材料的韧性得到明显改善；ＳｉＣ／Ａｌ合金陶瓷─金属层状复合材料的损伤形式主要是ＳｉＣ陶瓷层开裂、金属层桥接和裂纹偏转。     

溅射PZT薄膜的晶体结构和快速热处理

采用常温射频（ＲＦ）溅射法和快速热处理相结合的技术，在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上，制备出具有铁电性的ＰＺＴ薄膜。研究了快速热处理工艺条件对ＰＺＴ薄膜性能的影响。通过Ｚ射线衍射法、ＳＥＭ和ＡＥＳ等方法，分析了ＰＺＴ薄膜的晶体结构、微结构、薄膜和电极间的界面效应。     

p~＋－GaInAsSb／p－GaInAsSb／n－GaSb异质结红外控测器

ＧａＩｎＡｓＳｂ是红外探测器中重要的半导体材料之一。我们用水平常压金属氧化物化学气相淀积（ＭＯＣＶＤ）技术在ｎ型ＧａＳｂ衬底上成功地生长了ＧａＩｎＡｓＳｂ外延层，用ＰＬ谱、红外吸收谱、Ｘ射线衍射和扫描电子超声显微镜（ＳｃａｎｎｉｎｇＥｌｅｃｔｒｏｎＡｃｏｕｓｔｉｃＭｉｃｒｏｓｃｏｐｙ，ＳＥＡＭ）等实验手段对ＧａＩｎＡｓＳｂ外延层进行了表征。用ＧａＩｎＡｓＳｂ材料制作的红外探测器的光谱响应的截止波长达２．４μｍ，室温探测率Ｄ＊达１×１０９ｃｍＨｚ（１／２）／Ｗ，２．２５μｍ波长时的量子效率为３０％。本文首次给出了ＧａＩｎＡｓＳｂ外延层的扫描电子超声显微镜像（ＳＥＡＭ像），为扫描电子超声显微镜在半导体材料方面的应用开辟了一个新的领域。     

陶瓷薄膜与金属间的浸润性及其界面的研究

本文在对 ＴｉＮ、ＴｉＣ陶瓷薄膜与金属 Ａｇ、 Ｃｕ、 Ｎｉ、 Ｆｅ间的浸润性测量的基础上，用扫描电子显微镜（ＳＥＭ）、电子探针（ＥＰＭＡ）对其界面进行了观察。结果表明：浸润性较差的Ａｇ、Ｃｕ与ＴｉＮ、ＴｉＣ的界面平整，几乎没有发生相互扩散和化学反应；而浸润性较好的 Ｆｅ、Ｎｉ与 ＴｉＮ、ＴｉＣ的界面有明显的扩散和化学反应现象沿着ＴｉＮ、ＴｉＣ的晶界扩散；薄膜部分甚至全部溶入金属中。ＴｉＣ薄膜与Ｆｅ的界面反应程度大于ＴｉＮ 薄膜。     

The Influence of Interface Reactions Between Ceramics and Electrodes on Ceramic Properties

In a multilayered ceramic actuator structure, controlling the interface between the electrode and the ceramics is an essential technology for obtaining highly reliable ceramic actuators. The interface between Ag-Pd internal electrode and Pb(Ni_1/3Nb_2/3)O₃-PbTiO₃-PbZrO₃(PNN-PT-PZ), and the grain boundary in PNN-PT-PZ ceramics, were studied using TEM and EDS. We found that Pb diffuses into the Ag-Pd electrode during firing. At the initial sintering stage, Ag in Ag-Pd seems to diffuse into the piezoelectric ceramics along the grain boundary. Ag diffused in the grain boundary is segregated, and a small amount of Ag diffuses into the grain of the ceramics at the medium sintering stage. When compared to the thick film process, the interfacial reaction between Ag-Pd and PNN-PT-PZ is promoted more in the cofiring process than the thick film process. This is because more Pb vapors diffuse into Ag-Pd in the cofiring process than the thick film process. The addition of Ag into PNN-PT-PZ decreases the dielectric constant and affects the dielectric loss slightly.     

Scanning electron acoustic microscopy for the evaluation of domain structures in BaTiO3 single crystal and ceramics

As a non-destructive and subsurface detecting technique, the scanning electron acoustic microscopy (SEAM) method has been applied to study the ferrodomain structures in ferroelectric BaTiO3 single crystal and ceramics. The domain arrangements and the orientations of domain walls at different geometry structures in the BaTiO3 single crystal, and the relationships of domain structures with surface grains in the BaTiO3 ceramics, have been discussed by analysing the experimental results obtained at different operation conditions. The distributions of electron acoustic signals with modulation frequencies up to 1 MHz have been obtained. The relationship of the electron acoustic signal with incident electron energy has also been studied. Although the thermal wave coupling mechanism makes a certain contribution to the acoustic signal generations, the image contrast of ferrodomains is dominated by differences in the electrical properties of ferroelectric materials. © 1998 Kluwer Academic Publishers     

Application of Scanning Electron-Acoustic Microscopy to Biological Materials

The imaging methods and results for biological materials by scanning electron acoustic microscopy (SEAM) have been introduced in this paper. The images of the amplitude and phase of a plant leaf by SEAM show that the amplitude image involves more surface features but the phase image displays more subsurface structures. The laminated imaging experiments, which use the x- and y-components of SEAM signals with different reference phases, show the subsurface structures in different depths of biological materials, such as, plant leafs, biological tissues, etc. Using a photothermal technique, the thermal diffusion lengths of the samples of biological materials can be evaluated, by which the depths of the subsurface structures in the laminated images can be estimated. In addition, the damage areas of the leaf and muscles are also imaged by SEAM. For comparison, the second electron images of the same areas of the samples studied by SEAM are also obtained. The images show that SEAM is sensitive to micro-structures of surface, and also subsurface, structures of biological materials.     

Study of overgrowth heterostructure InSb/GaAs by scanning electron acoustic microscopy

An overgrowth InSb epilayer on GaAs substrate with large lattice-mismatch was grown by metalorganic chemical vapor deposition (MOCVD), and the heterogeneous crystalline state was observed by scanning electron acoustic microscopy (SEAM). The middle stage of relaxation of the large mismatch InSb/GaAs epilayer is observed by SEAM images of crystalline state of the buried subsurfaces. A macroscopical heterogeneous distribution is formed by large compression stress fields. It was a very important result to observe and study semiconductor epitaxial heterostructures by SEAM uniquely imaging mechanism.     

与Ag内电极共烧对ZnVSb压敏陶瓷显微结构及性能的影响

研究共烧影响及其机理是开发多层片式压敏电阻的基础和关键。采用XRD、SEM、EDS研究了与Ag内电极共烧对ZnVSb陶瓷显微形貌、晶体结构及烧结性能的影响。结果表明,与Ag内电极共烧不影响ZnVSb陶瓷的相组成,但阻碍ZnVSb陶瓷烧结。Ag通过富V液相扩散并恶化其与ZnO晶粒的浸润性,从而阻碍ZnVSb陶瓷的致密化进程。Zn在Ag内电极中不存在扩散,而Sb在其中的扩散破坏了ZnVSb陶瓷原有的成分配比。研究结果为ZnVSb基片式压敏电阻开发奠定了基础。     

铁电半导体陶瓷材料电声成像中电声信号的产生

本文利用扫描电声显微镜成像技术对铁电半导体陶瓷材料进行了无损成像观察和分析。通过对不同条件下获得的电声像的讨论，得出在这种材料的电声成像中，热波耦合机制和压电耦合机制对电声信号的产生均有着贡献，但热波耦合机制占主导地位。另外扫描电声显微镜在对材料的亚表面缺陷无损观察方面有着其它观察手段所无法比拟的优点。     

Near-field acoustic and piezoresponse microscopy of domain structures in ferroelectric material

Three kinds of near-field microscopy imaging mode including SEAM (Scanning electron acoustic microscopy), PFM (Piezoresponse force microscopy) and SPAM (Scanning probe acoustic microscopy) have been developed to investigate domain structures of ferroelectric ceramics, crystals and thin films in our studies. The domain imaging mechanisms are presented individually in three imaging modes. Sub-surface micro-domain configuration of ferroelectric BaTiO₃ ceramics and single crystal and their dynamic behavior under external fields were clearly visualized by SEAM. Ferroelectric domain structures of ferroelectric PZT thin film and PMN-PT single crystal were characterized by PFM. Nanoscale switching behavior and local field-induced nanoscale displacement behavior of domain structures in ferroelectric thin film were studied by PFM. Antiparallel domain patterns in ferroelectric transparent PLZT ceramics were also characterized by SPAM. The combination of SEAM, PFM and SPAM in application to imaging domain structures undoubtedly enrich our understanding of the nature of piezoelectricity and ferroelectricity at submicro-, even nano-meter scale.     

Relationships between interfacial interaction, electrode formulation and cofiring mismatch of relaxor-based multilayer ceramic devices

The drive for high reliability of multilayer ceramic chips requires perfect cofired heterogeneous interfaces that can be obtained by a reliable cofiring processing. The cofiring behavior between Pb-based relaxor ferroelectric and Ag-Pd electrode was investigated. The results obtained indicated evident interdiffusion and chemical reactions at the interface. These interfacial interactions caused the formation of an interlayer, especially for the addition of a suitable amount of ceramic powder into the Ag-Pd paste. An analysis of interfacial stress distribution demonstrated that a moderate interfacial layer tends to alleviate the cofiring mismatch between ceramic layers and electrode layer. In addition, the type of cofired interface between the ferroelectric and the Ag-Pd alloy electrode was confirmed to be a mixture of diffusion and compound type.     

Design and fabrication of multilayer actuator using floating electrode

PZT (lead zirconate titanate) multilayer actuators were of interest due to their small volume, fast response, low power consumption and low driving voltage. But this multilayer actuator had some problems. However, due to internal stress around electrodes, crack and delamination were very important issues. Around the edge of conventional inter-digital electrodes, non-uniform electric field generates the stress concentration, which causes the ceramic crack and delamination. The internal stress distribution in multilayer actuator was analysed by a numerical simulation. And by using float electrode, multilayer actuator was manufactured to decrease internal stress concentration of inter-digital electrode. The float electrode could suppress the electric field concentration and cracking in the actuator.

Destruction mechanism in multilayer ceramic actuators has been investigated under cyclic electric fields. Crack propagation has been observed dynamically by using optical microscopy, and the accompanying characteristic of acoustic emission was measured.     

Interfacial construction of gold nanoshells on 3-aminopropyl triethoxysilane modified ITO electrode surface for studying cytochrome b562 electrochemistry

An interface of gold nanoshells (GNSs) was constructed on the surface of the 3-aminopropyl triethoxysilane (APTES) modified ITO glass substrates by a simple self-assemble method to form the GNSs-coated ITO electrode. UV-vis spectroscopy, scanning electron microscopy (SEM), and cyclic voltammetry were used to characterize the GNSs interface architectures. SEM and UV-vis spectroscopy showed that an interconnected and stable GNSs interface was formed on the APTES modified ITO glass substrate. The cytochrome b562 (Cyt b562) was selected to observe electron transfer reactions of redox protein at the GNSs-coated ITO electrodes. Quasi-reversible electrochemistry of Cyt b562 was obtained and its electrochemical behaviors were discussed.