高温工作环境中FeCo基纳米晶合金的介观结构相

利用原子力显微镜和高分辨场发射电子显微镜系统地研究了高温退火的FeCo基纳米晶合金薄带的介观结构。发现高温退火的FeCo基纳米晶合金中具有纳米晶粒的团聚结构,尺寸约为200hm2由x射线衍射结果和目前已有的实验成果推断这种团聚结构中大约有104—105个纳米晶粒及包围这些纳米晶粒的非晶相。这种团聚结构与退火温度的高低具有十分密切的关系,因此称之为高温工作环境中FeCo基纳米晶合金的介观结构相,简称介观结构相。     

不同掺杂方式C60 Langmuir-Blodgett复合膜性质比较

C60是碳的一种同素异形体,具有很多奇特的物理化学性质,[1]Langmuir-Blodgett膜（LB膜）是形成C60分子有序结构的一种有效的方法。[2]通过研究沉积在亲水玻璃基底上的单层C60/SA LB复合膜和单层C60/AA LB复合膜的π-A曲线和原子力显微镜（AFM）图片,发现C60/SA LB复合膜排列更为均匀有序,而C60/AA LB复合膜排布不如C60/SA LB复合膜均匀有序,但是膜的厚度较薄。     

Switching Phenomena of CuTCNQ Induced Mainly by the Interaction among Microcrystaline Grains

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Bifurcation analysis of a microcantilever in AFM system

The atomic force microscope system (AFM) has become a popular and useful instrument to measure the intermolecular forces with atomic resolution that can be applied in electronics, biological analysis, materials, semiconductors, etc. This paper studies the bifurcation phenomenon and complex nonlinear dynamic behavior of the probe tip between the sample and microcantilever of an atomic force microscope using the differential transformation method. The dynamic behavior of the probe tip is characterized with reference to bifurcation diagrams, phase portraits, power spectra, Poincaré maps, and maximum Lyapunov exponent plots produced using the time-series data obtained from differential transformation method. The results indicate that the probe tip behavior is significantly dependent on the magnitude of the vibrational amplitude. Specifically, the probe tip motion changes from T-periodic to 3T-periodic, then from 6T-periodic to multi-periodic, and finally to chaotic motion with windows of periodic motion as the vibrational amplitude is increased from 0 to 5.0. Furthermore, it is demonstrated that the differential transformation method is in good agreement for the considered system.     

Silica glass interaction with calcium hydroxide: a surface chemistry approach

The study of the interaction between silica glass and saturated Ca(OH)₂ solutions can be a useful approach to resolve the problem of the adhesion between lime-sand mortar and clay bricks. Since it is reasonable that the silica–calcium hydroxide system well simulates a brick–mortar system, experimental observations concerning the interaction of silica glass and this strong basic solution should be of value for the comprehension of the chemical reactions that could take place at the mortar–brick interface, maybe affecting the adhesion between the two building materials. We demonstrated the effects of saturated Ca(OH)₂ solutions on commercial pure silica glass (fused silica) and on silica films obtained via a sol–gel process by means of dip-coating. Silica samples were dipped in the solutions at different temperatures (room temperature, 60 and 80 °C) and at different time intervals (1 and 21 h) and then they were analysed by means of surface techniques: X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and atomic force microscopy (AFM). It has been shown that Ca(OH)₂ reacts with the silica glass network. The experimental results clearly show a very different behaviour of sol–gel silica with respect to fused silica, probably because of their different nanostructure. Many problems concerning the interaction of silica and Ca(OH)₂ are still to be solved, but the results of this research strengthen the idea that adhesion between lime-sand mortar and clay bricks is caused not only by carbonation of calcium hydroxide contained in the mortar, but even by some chemical reactions involving the brick constituents and calcium hydroxide itself. The final products, calcium silicates, may induce a chemical continuity between lime-sand mortar and clay bricks.     

A novel colloid probe preparation method based on chemical etching technique

Several fundamental problems in hydrophobic force measurements using atomic force microscope （AFM） are discussed in this paper. A novel method for colloid probe preparation based on chemical etching technology is proposed, which is specially fit for the unique demands of hydrophobic force measurements by AFM. The features of three different approaches for determining spring constants of rectangular cantilevers, including geometric dimension, Cleveland and Sader methods are compared. The influences of the sizes of the colloids on the measurements of the hydrophobic force curves are investigated. Our experimental results showed that by selecting colloid probe with proper spring constant and tip size, the hydrophobic force and the complete hydrophobic interaction force curve can be measured by using AFM.     

Formation of ots self-assembled monolayer on glass surface investigated by AFM

The whole process of octadecyltrichlorosilane (OTS) self-assembled monolayer formation on glass surface was clearly revealed by using Atomic Force Microscope (AFM). The growth regularity pattern of OTS self-assembled monolayer on glass substrate was obtained by analyses of the AFM images and the average surface mean roughness (R _avg) of the sample surfaces. The adsorption feature of OTS molecules on the substrate surface during the initial reaction period was probed through a comparison experiment. Project supported by the Scientific Research Foundation for Retured Overseas Chinese Scholar, State Education Committee.     

钕掺杂氧化锌薄膜的形貌分析

通过XRD和AFM分析了Nd掺杂ZnO薄膜的表面形貌,表明随着Nd掺杂量的增加,ZnO薄膜的结晶度变差,薄膜表面变得粗糙,晶格畸变增大。     

原子力显微镜在高分子领域的应用进展

原子力显微镜(AFM)是在扫描隧道显微镜(STM)基础上发明的又一种纳米级高分辨率显微技术，目前已在高分子领域获得了广泛的应用．AFM无需对样品进行任何预处理即可对各种材料进行微观区域的表面形貌及机械性能探测，或者直接进行纳米操纵．表文则从表征聚合物聚集态、物理性质、分子量及其分布等几个方面综述了当前AFM应用于高分子材料研究的最新进展和新技术．