AFM and TEM study of the surface of zirconium cans of fuel elements

The surface morphology and the inner structure of oxide layers on cans made of E110 zirconium alloy are investigated by atomic force microscopy and transmission electron microscopy. It is found that the mechanism of formation of the structure of oxide layers in the course of corrosion tests depends on the mode of pretreatment of zirconium cans.     

The morphology of mass selected ruthenium nanoparticles from a magnetron-sputter gas-aggregation source

We have investigated the morphology of mass selected ruthenium nanoparticles produced with a magnetron-sputter gas-aggregation source. The nanoparticles are mass selected using a quadrupole mass filter, resulting in narrow size distributions and average diameters between 2 and 15 nm. The particles are imaged in situ by scanning electron microscopy and scanning tunneling microscopy (STM) as well as ex-situ using transmission electron microscopy (TEM). For each distribution of mass selected nanoparticles, the height determined by STM and the width determined by TEM are seen to be similar throughout the mass range investigated. The particles are found to have a well-defined morphology for diameters below approximately 6 nm. Larger nanoparticles are less well-defined having rough surfaces, unlike the equilibrium morphology determined from the Wulff construction. The morphology of the particles is, in general, believed to be determined by the conditions inside the gas-aggregation source and the morphology is retained as the particles are soft-landed on the substrate.     

Influence of the surface microroughness of a Si(001) substrate on the morphology of CaF2 epitaxial layers under high-temperature growth conditions

The influence of the surface microroughness of Si(001) substrates on the morphology of CaF₂ epitaxial layers is investigated in the high-temperature growth mode. The atomic-force microscopy method is used to demonstrate that the silicon surface relief substantially affects the nucleation, growth, and formation of the morphology of CaF₂ layers.     

H3O+-dependent morphological change in the electrochemical deposition of iron

By in situ optical microscopy and scanning electron microscopy, we investigate the morphology of the iron electrodeposit grown at different H₃O⁺ concentration in the electrolyte. The chemical composition of the electrodeposit is analyzed by X-ray diffraction and Mössbauer spectroscopy. It seems that the morphological transitions observed in this system do not relate to the oxidation/passivation of the metallic deposit during the growth. The possible origin of the dependence of deposit morphology on the H₃O⁺ in the electrolyte is discussed.     

光散射在聚合物共混过程中形态发展研究的应用

本文应用光散射法和电子显微镜对聚丙烯/尼龙1010(PP/PA1010=90/10,体积比)共混体系的微观形态发展进行了研究。利用激光背散射在线系统采集了散射图象,由散射光斑的积分强度和Debye Bueche理论计算的相关距离讨论了共混物形态演化过程。结果表明,这一体系在共混初期(即1分钟以前)形态有较大变化,这一阶段是聚合物在密炼机中软化、变形和熔融混合的过程。由不同时刻采样并进行电镜观察发现,在共混1分钟以后,共混物的形态确实变化不大,这说明光散射法用于研究聚合物共混过程中的形态发展是可行的。     

Influence of the grain-size and chemical composition of a MgO coating on the structure-phase state and elemental composition of the ground layer formed on an electric steel surface

The surface morphology, phase state and elemental composition, and substructure of the ground layer of anisotropic electric steel (AES) samples have been studied via scanning electron microscopy, atomic force microscopy, transmission electron microscopy, electron probe microanalysis, and x-ray diffractometry. High-temperature annealing of MgO coatings with different grain-size distributions and chemical compositions was found to lead to formation of a single-phase layer of forsterite (Mg₂SiO₄) on the AES surface. It has been revealed that the morphology and substructure of a forsterite layer depend on the grain-size distribution and chemical composition of magnesium oxide and the conditions used in preparation of MgO suspensions. When added to MgO suspensions, TiO₂ and Na₂B₄O₇ impurities promote formation of a denser coating substructure. The increased mixing speed used in suspension preparation improves the surface homogeneity of a ground layer only if a suspension contains MgO grains of different size.     

Growth of ZnO Nanostructures on Porous Silicon and Oxidized Porous Silicon Substrates

We have investigated an oxidation of substrate effect on structural morphology of zinc oxide (ZnO) rods. ZnO rods are grown on porous silicon (PS) and on thermally oxidized porous silicon substrates by carbothermal reduction of ZnO powder through chemical vapour transport and condensation. Porous silicon is fabricated by electrochemical etching of silicon in hydrofluoric acid solution. The effects of substrates on morphology and structure of ZnO nanostructures have been studied. The morphology of substrates is studied by atomic force microscopy in contact mode. The texture coefficient of each sample is calculated from X-ray diffraction data that demonstrate random orientation of ZnO rods on oxidized porous silicon substrate. The morphology of structures is investigated by scanning electron microscopy that confirms the surface roughness tends to increase the growth rate of ZnO rods on oxidized PS compared with porous silicon substrate. A green emission has been observed in ZnO structures grown on oxidized PS substrates by photoluminescence measurements.     

Dependence of the atomic structure and surface relief of platinum foils on the annealing and rolling conditions

The effect of cold rolling, polishing, and thermal annealing conditions on the atomic structure and surface geometry of platinum foils has been studied. The surface morphology has been analyzed using low-energy electron diffraction, atomic force microscopy, and scanning tunneling microscopy. The chemical composition of the surface has been evaluated by Auger electron spectroscopy. It has been demonstrated that a variation in the conditions used for the preparation of the samples makes it possible to produce surfaces with different degrees of perfection from atomically smooth to rippled, fractal, and diffraction-disordered surfaces.     

Surface Characterization and Optical Study on Electrospun Nanofibers of PVDF/PAN Blends

Different concentrations of electrospun nanofibers of poly(vinylidene fluoride) (PVDF)/polyacrylonitrile (PAN) blends were prepared. The surface morphology of the nanofibers was studied by optical microscopy and scanning electron microscopy (SEM). Atomic force microscopy (AFM) was used to study the surface roughness. The change in the functional groups of PVDF after blending with PAN was investigated by Fourier transform infrared (FTIR). The wettability was examined to characterize the surface morphology of the blends. The effect of PAN content on the blend fiber was also studied for UV-vis absorption spectra before and after exposure to UV radiation.     

铜纳米粒子的水热法制备及其结构表征

采用水热法制备了不同形貌和结构的铜纳米粒子,并通过扫描电子显微镜(SEM)、X射线衍射分析仪(XRD)以及紫外-可见光学吸收谱对其形貌、结构和光学性质进行了表征。考察了反应物配比以及反应温度和时间对产物形貌的影响。     

Investigating the surface morphology and magnetic contrast of epitaxial ferromagnetic structures

The surface morphology of nickel thin films is investigated via atomic force microscopy. The multistage film growth mechanism is found to be dependent on substrate temperature and film thickness. It is shown that conduction electron scattering from the irregularities of the outer and inner surfaces of structures are influenced by the surface morphology and determined by an integrated contribution of the surface’s fluctuation density spectrum. The morphology influence can be decreased under certain growth conditions so that the residual mean free path of conduction electrons can reach 1000 nm, exceeding the film thickness. Epitaxial nanostructures with high electron mobility have been fabricated. Investigation of their magnetic structure has shown that their magnetic domain dimensions are less than the residual mean free path of electrons determined by the surface morphology.     

Effect of ultrasonic treatment on the morphology of casein particles

In this study, the effect of ultrasonic treatment duration on the morphology of self-assembled casein particles was investigated by atomic force microscopy (AFM), low vacuum scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the case of AFM images, the particle analysis which was carried out by the SPIP program showed that the self-assembled casein particles after being ultrasonically treated for 2 min got smaller in size compared to the casein particles that have not been exposed to any ultrasonic treatment. Surprisingly, however, increasing the ultrasonic time exposure of the particles resulted in an opposite effect where larger particles or aggregates seemed to be present. We show that by comparing the results obtained by AFM, SEM and TEM, the information extracted from the AFM images and analyzed by SPIP program give more detailed insights into particle sizes and morphology at the molecular level compared to SEM and TEM images, respectively.     

Investigation of the morphology of polymer blends by nonconventional techniques

The morphology of polyethylene-silicone blends has been investigated by combining scanning electron microscopy with measurements of permeability to methanol vapor and selective extraction of the silicone phase by diethyl ether. The results show that scanning electron microscopy is the most suitable technique to characterize the microstructure of the blends (size and shape of the dispersed phase). On the other hand, permeability measurements provide the most useful information about the way morphology is changing with composition of the blends and about the composition corresponding to the maximum level of co-continuity of the two phases. Selective extraction of the dispersed phase is not a reliable technique in the system investigated because the extraction process induces physical damage in the matrix.     

Investigations on the Interface Microstructure of Stainless Steel/Aluminum Joints Created by the Surface Activated Bonding Method

Stainless steel and aluminum have been bonded by the surfaceactivated bonding method. Both transmission electron microscopy (TEM)and scanning electron microscopy (SEM) have been used to investigatethe interface microstructure of the as-bonded and annealed joints. Aperfect interface did not show any microcracks or porosity for theas-bonded joints. An 10 nm thick intermediate layer composed ofmainly silicon and certain amounts of oxygen and carbon was foundbetween stainless steel and aluminum by means of high resolutionelectron microscopy (HRTEM). The interface morphology of the jointsvaried gradually as the bonded joints are heated at elevatedtemperature. When heated to 573 K, individual precipitate-likefluctuation at the interface area was detected, with slightmodification of the interface morphology. Bulky intermetalliccompounds finally formed throughout the original interface boundarywhen heated to 873 K and contributed to the weakening of theinterface boundary of the joints.     

原子力显微镜的研究型教学实验设计探讨

介绍了原子力显微镜的基本工作原理及其应用,阐述了在大学物理实验课程中开设原子力显微镜有关实验的必要性和重要意义,结合在教学和科研方面的经验,指出了在大学物理实验课中开设原子力显微镜有关实验的设计。最后,以分析半导体薄膜的形貌特性为例,探讨了原子力显微镜在大学物理实验课中的具体应用。     

Influence of solvents on the morphological properties of AgBr nano-structures prepared using ultrasound irradiation

Nano-structures of AgBr have been prepared by reaction between AgNO₃ and KBr under ultrasound irradiation. Particle sizes and morphology of nanoparticle are depending on temperature, power of sonicating, reaction time and concentration. The effects of these parameters in growth and morphology of the nano-structures have been studied. Results suggest that an increasing of temperature, sonication power and concentration led to a decreasing of particle size. The samples were characterized with powder X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Factors affecting the growth of micro/nano-sized tungsten whiskers synthesised by vapour deposition

In this paper, a large number of the micro/nano-sized tungsten single-crystalline whiskers were fabricated via a vapour deposition method. The morphology and structure of the whiskers were investigated using scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The factors affecting the growth of tungsten whiskers were systematically studied, including temperature, holding time and the position of Si substrates. Results indicated that temperature, holding time and position of the Si substrates have significant effects on the growth of tungsten whiskers.     

Angle dependent laser nanopatterning of poly(ethylene terephthalate) surfaces

Interference effects can lead to the formation of ripple structures at laser-irradiated poly(ethylene terephthalate) surfaces. Poly(ethylene terephthalate) surface was irradiated with linearly polarized light of a pulsed 157 nm laser. In a certain range of irradiation parameters, the irradiation resulted in the formation of coherent ripples patterns. The dimension of the pattern depends on the angle of the laser beam incidence. The surface morphology of the nano-patterned poly(ethylene terephthalate) was analyzed by atomic force microscopy and focused ion beam-scanning electron microscopy. Oxygen concentration in the modified polymer surface was studied by angular resolved X-ray induced photo-electron spectroscopy. Gold nano-layers were consecutively sputtered onto the laser irradiated poly(ethylene terephthalate) surfaces. The morphology of the sputtered gold nano-layers was investigated with atomic force microscopy too. We found that the morphology of the gold nano-layers changes and depends on the surface pattern of the laser irradiated poly(ethylene terephthalate). Formation of gold “nano-hills” is observed at the ridges of the ripple structures. The amount of oxygen together with the morphology of prepared polymer pattern may be the dominant factors controlling the gold layer growth. The present results are compared with those obtained earlier on PET irradiated with krypton fluoride laser.     

Large-scale array of highly oriented silicon-rich micro/nanowires induced by gas flow steering

Si-rich nanowires have been synthesized by decomposition of silicon monoxide (SiO) at a temperature of 1080 °C, with argon (Ar) as the carrier gas. The morphology was observed to be highly oriented on a macro-scale by scanning electron microscopy (SEM). The formation mechanisms of the ordered morphology were discussed by means of energy dispersion X-ray spectroscopy (EDS), Raman scattering and high-resolution transmission electron microscopy (HRTEM) and we attributed this to the steering of the gas flow.     

Characterization of Ce O2thin films on a sapphire

Thin layers of CeO2were deposited on the R-plane of a sapphire substrate. The films were tested by x-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. The films were found to be epitaxial with fine-grain morphology of the surface.