Analysis of Thin Films on Metal Surfaces

External reflection infrared spectroscopy was used in combination with other surface analysis techniques such as ellipsometry, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS) to determine the structure of organofunctional silanes adsorbed onto 2024 aluminum and titanium-6 Al, 4V mirrors. The results obtained indicated that the adsorption of γ-aminopropyltriethoxysilane (γ-APS) onto aluminum was a strong function of pH and adsorption time. Films formed by adsorption of γ-APS at pH = 8.5 were composed of polysiloxanes containing amine hydrochlorides. The structure of films formed by adsorption of γ-APS at pH-10.4 depended on time. Films obtained after one minute were composed of polysiloxanes that did not interact strongly with the oxide but during 15 minutes adsorption the air-formed oxide was dissolved and copper accumulated near the surface of the mirrors. Films formed by the adsorption of γ-glycidoxypropyltrimethoxysilane (γ-GPS) onto aluminum were composed of polysiloxanes that did not interact strongly with the oxide. The structure of films formed by adsorption of γ-APS onto titanium did not depend on adsorption time. Films formed at pH = 10.4 were composed of low molecular weight oligomers that gradually polymerized to polysiloxanes during atmospheric exposure.     

Synthesis of Strontium Barium Niobate Thin Films through Metal Alkoxide

Highly oriented Sr_0.5Ba_0.5Nb₂O₆ (SBN50) thin films have been prepared using a sol-gel method. A homogeneous and stable strontium barium niobate (Sr_1-xBa_xNb₂O₆, SBN) precursor solution could be prepared via the reaction control of metal alkoxides. The SBN precursor was stabilized by the coordination of the 2-ethoxyethoxy group to metals. SBN thin films on MgO(100) crystallized to a mixture of orthorhombic and tetragonal phase at 700°C and then transformed completely to the tetragonal phase of tungsten bronze at 1000°C. Two crystal lattice planes of SBN were intergrown at an orientation of 18.5° on MgO(100). SBN50 thin films on Pt(100)/MgO(100) substrates exhibited the P-E hysteresis.     

用微量-热分析(μTA)表征聚合物膜

微量－热分析是一种结合原子力显微镜显示能力和热分析表征能力的崭新技术。它以原子力显微镜显示材料的形貌、热传导和热扩散的区域分布,并以微量－热机械分析及微量－调幅热分析测量材料相应位置的物理及化学性质变化     

Changes in the Peeled Surfaces of Copper Thin Films Deposited on Polyimide Substrates After Heat Treatment

Peel strength between a copper (Cu) thin film and a polyimide (pyromellitic dianhydride-oxydianiline, or PMDA-ODA) substrate is reduced by heat treatment at 150°C in air. In this work, we investigated the peel strength, the morphology of the interface between Cu films and polyimide substrates using optical microscopy and electron microscopy, and chemical change of the interface using Auger electron spectroscopy (AES) and micro X-ray photoelectron spectroscopy (XPS). The analysis showed that CuO “lumps” were present on the peeled surface of PMDA-ODA after heat treatment at 150°C in air. The peeled surfaces of other polyimide substrates were also analyzed: biphenyl dianhydride-para phenylene diamine (BPDA-PDA) and biphenyl dianhydride-oxydianiline (BPDA-ODA). CuO lumps were present on the peeled surface of BPDA-ODA after the heat treatment, but not that of BPDA-PDA. Compared with the adhesion strength for the Cu thin film, the adhesion strength was high for the Cu/PMDA-ODA and Cu/BPDA-ODA laminates, but the adhesion strength was very low for the Cu/BPDA-PDA laminate. This low strength is the reason that CuO lumps were not detected on the peeled surface of the BPDA-PDA substrate. These CuO lumps were related to the adhesion degradation of the Cu/polyimide laminates after the heat treatment.     

不同离子掺杂TiO_2薄膜及光催化活性研究

采用溶胶-凝胶法分别制备了掺杂Fe^3＋、Cu^2＋、Zn^2＋、Ce^3＋和La^3＋5种不同离子的纳米级TiO2薄膜,使用TiO2薄膜对亚甲基蓝溶液进行光催化试验。研究表明,在5种掺杂离子中,其La^3＋的掺杂效果最好,当La^3＋的适宜含量为1.8%（质量分数）时,掺杂与未掺杂的XRD图谱基本一致;掺入La^3＋离子使得TiO2的晶粒变小,可抑制晶相向金红石相转变;随着焙烧温度的升高TiO2晶粒逐渐变大,温度为700℃时,其粒径为27.6nm,TiO2为混合晶型（锐钛矿型和金红石型）,其活性最高。     

Thin Film Growth on Quasicrystalline Surfaces

The surfaces of quasicrystals have proved to be a very interesting playground for thin film growth. They offer a complex potential energy surface where heterogeneous nucleation of islands at specific quasilattice sites is frequently observed. These islands tend to locally adopt the symmetry of the quasicrystalline substrate. For some specific adsorbates, a complete 2-dimensional quasiperiodic metal overlayer is even formed. Other interesting phenomena are also observed in the multilayer regime. This includes the formation of novel structures, like 1-dimensional quasiperiodic Cu films or Bi allotropes, the formation of nanoscale crystalline domains with 5-fold rotational epitaxy, or the occurrence of quantum size effects influencing the film morphology. This article presents a short review of some of the achievements in thin film growth on quasicrystalline surfaces that the discovery of quasicrystals by Dan Shechtman has enabled.     

SEM Analysis of Oxide Thin Films and Reactions

The determination of orientation relationships between thin oxide films and the underlying single-crystal oxide substrates using electron backscattered diffraction (EBSD) in scanning electron microscopy (SEM) is discussed. In these well-defined systems, complementary information concerning the local chemistry can be obtained using high-resolution backscattered electron (BSE) imaging. Recent studies have shown the value of using EBSD patterns (EBSPs) in SEM.     

硅烷薄膜

制备了一种涂膜．其特征为：涂膜由含至少—个活性基团选自卤素原子、烷氧基和异氰酸酯基的硅烷化合物形成。涂膜分子部分通过硅、锗、锡、钛和锆元素中的至少一种以共价键方式附着于底材表面，部分相互聚合。涂膜透明．膜厚1nm-0．5μm，膜至少可以通过5次耐磨试验．方法为采用1：1的糖和酱油的混合物．在300℃下加热20min．然后冷却．烘干并粘附的污迹可以用湿布手工擦拭除去。     

The Behavior of Water on Metal Surfaces

The role of metals (pure, alloyed, or in the form of mixtures) is well established in catalytic processes. The production of fuels, plastics, fertilizers, etc., on a large scale rests on the catalytic effect of metals. The breakthrough of bimetallic and multimetallic catalysts [1] is the result of a great body of basic research that aimed to shed light on the mechanisms responsible for their activity, selectivity, and stability. From another point of view the sensitivity of catalytic reactions to surface parameters has been well known since early times [2]. Crystallographic structure, surface morphology and composition, metal dispersion, etc., dramatically affect these three characteristics. Generally speaking, any loss of structural order and symmetry can be associated with localized electronic states that determine not only the chemical but also the electronic properties of the surface [3].     

Berkovich Nanoindentation on AlN Thin Films

Berkovich nanoindentation-induced mechanical deformation mechanisms of AlN thin films have been investigated by using atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (XTEM) techniques. AlN thin films are deposited on the metal-organic chemical-vapor deposition (MOCVD) derived Si-doped (2 × 10¹⁷ cm⁻³) GaN template by using the helicon sputtering system. The XTEM samples were prepared by means of focused ion beam (FIB) milling to accurately position the cross-section of the nanoindented area. The hardness and Young’s modulus of AlN thin films were measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM) option. The obtained values of the hardness and Young’s modulus are 22 and 332 GPa, respectively. The XTEM images taken in the vicinity regions just underneath the indenter tip revealed that the multiple “pop-ins” observed in the load–displacement curve during loading are due primarily to the activities of dislocation nucleation and propagation. The absence of discontinuities in the unloading segments of load–displacement curve suggests that no pressure-induced phase transition was involved. Results obtained in this study may also have technological implications for estimating possible mechanical damages induced by the fabrication processes of making the AlN-based devices.     

PbS薄膜的研究进展

通过对PbS薄膜的结构特征、制备方法、应用领域的综述,提出并设计了水热法、溶胶凝胶法和水热电沉积法等几种简单的制备PbS薄膜的新方法,展望了PbS薄膜的发展前景,PbS薄膜将向制备简单化、功能完善化、应用多样化的方向发展.     

铁电薄膜的微图形化研究

铁电薄膜在微电子和光电子技术中有着重要的或潜在的应用,可以制作随机存取存储器,热释电阵列探测器,铁民微电子机械系统等,在这些器件的制作过程中,铁电薄膜的微图形化是非常重要的一环,本文简要介绍了几种重要的铁电薄膜微图形化方法及有关研究结果,并比较了这些方法的优缺点。     

Preparation of Thin Mullite Films

Aluminosilicate glass films having compositions approximately that of mullite produced by reactive sputtering of aluminum-silicon alloys are discussed. Data are given on the speed of deposition under certain conditions for a variety of metal and ceramic substrates. Mullite crystals with the needle habit are formed from the initial amorphous film by subsequent heat treatment of about 1 hour at temperatures of 1100° to 1400°C. The number and size of the crystals are affected by firing conditions, composition, and thickness of the film and by nucleating agents such as carbon on the surface of the film as indicated by transmission electron micrographs of unsupported films. The reaction of the oxide films with some supporting ceramic substrates has also been studied.     

Carbon Monoxide Oxidation on Copper Oxide Thin Films Supported on Corrugated Cerium Dioxide {111} and {001} Surfaces

Thin films of CeO₂with and without a thin layer of copper oxide were prepared by rf magnetron sputtering on surfaces of α-Al₂O₃(sapphire) substrates. Careful characterisation of the surfaces was performed down to the atomic level using high-resolution electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Surprisingly, the as-deposited, corrugated ceria surfaces, nominally (001), consist exclusively of {111}-type lattice planes, but, upon annealing at 800°C, a well-defined portion of (001) surfaces are formed. Oxidation of carbon monoxide to carbon dioxide was studied, having the prepared films in a stirred batch reactor. A batch reactor was chosen so that the conversion over the small sample surface area (ca 10⁻⁴m²) could be monitored as a function of the reaction time. The activity of copper oxide on annealed ceria surfaces is markedly higher than on nonannealed surfaces, indicating a favourable synergetic effect between the ceria (001) surface and the copper oxide phase.     

BiFeO3薄膜研究进展

BiFeO3是少数的在室温下同时具有铁磁性和铁电性的铁磁电材料之一,在信息存储、传感器和自旋电子器件等方面都有潜在的应用前景.本文通过对BiFeO3薄膜的结构、磁性起源、制备工艺和应用领域等方面的综述,提出并设计了水热法和仿生法这两种新的制备BiFeO3薄膜的湿化学方法,并展望了BiFeO3薄膜今后的研究和发展趋势.     

铁电薄膜材料的研究进展

近年来，随着铁电薄膜制备技术的发展，其应用领域不断扩大。综述了近年铁电薄膜材料研究进展情况，并指出存在的问题及其发展方向。     

铁电薄膜材料的研究进展

近年来，随着铁电薄膜制备技术的发展，其应用领域不断扩大。本文综述近年来铁电薄膜材料研究进展情况，并指出存在的问题及其发展方向。     

Deposition of Gold Nanoparticles on Thin Polyaniline Films

Local and bulk deposition of gold particles was accomplished by the spontaneous reaction between chemically reduced polyaniline (PAN) thin films and AuCl. PAN layers were deposited on glass, indium tin oxide (ITO), and glassy carbon (GC) by the Langmuir–Blodgett method and spin-coating. Characterization of the PAN films was carried out by microscopy, UV–vis spectroscopy, and electrochemistry. We found that the nature of the gold deposit was greatly affected by the thickness of the PAN. Scanning electrochemical microscopy was used as a means of locally depositing gold nanoparticles on an unbiased PAN film by anodically dissolving a gold micro-electrode. This represents a generic approach whereby a variety of metal micro- and nanoparticles can be locally deposited on insulating supports.     

Thin Films in Electron Microscopy

Thin films play an important role in electron microscopy as they can be used to improve the contrast and stability of specimens, as well as to make specimens electrically conductive. In order to avoid overlapping of specimen and coating structures, it is necessary to understand how thin films are formed in the various coating technologies and how to create them reproducibly as part of the different preparation techniques for electron microscopy. In contrast, electron microscopy can be applied to learn more about the structural details of thin films used, for instance, in the optical coating industry. Heat shock fracturing and Pt-C surface replication of the cross sections resulted in reliable transmission electron micrographs (TEM) of the coating microstructure. These studies demonstrate that, under optimal conditions, it is possible to find a correlation between the measured optical properties and the microstructure of the coatings. TEM replica investigations reveal single events, so they can be useful if discrepancies in the (statistical) physical data have to be investigated.