Search results for "MICROSCOPE"
showing 10 items of 1412 documents
The zero field self-organization of cobalt/surfactant nanocomposite thin films
2009
Cobalt nanostructures have been prepared by a chemical route based on the Co(II) reduction in the confined space of cobalt bis(2-ethylhexyl)sulfosuccinate (Co(DEHSS)(2)) reverse micelles dispersed in n-heptane. This procedure involves the rapid formation of surfactant softly coated Co nanostructures followed by a slow separation process of the magnetic-field responsive Co/surfactant nanocomposites from the liquid phase. The detailed structure of thin films of the Co/surfactant nanocomposites has been investigated by scanning force microscopy (SFM). The thin films were characterized by different anisotropic features. Micrometric long domains of self-aligned ellipsoidal NPs (tens of nanometer…
3D superconducting hollow nanowires with tailored diameters grown by focused He+ beam direct writing
2020
Currently, the patterning of innovative three-dimensional (3D) nano-objects is required for the development of future advanced electronic components. Helium ion microscopy in combination with a precursor gas can be used for direct writing of three-dimensional nanostructures with a precise control of their geometry, and a significantly higher aspect ratio than other additive manufacturing technologies. We report here on the deposition of 3D hollow tungsten carbide nanowires with tailored diameters by tuning two key growth parameters, namely current and dose of the ion beam. Our results show the control of geometry in 3D hollow nanowires, with outer and inner diameters ranging from 36 to 142 …
Preparation of Graphene Nanoribbons (GNRs) as an Electronic Component with the Multi-walled Carbon Nanotubes (MWCNTs)
2015
Abstract Carbon nanotubes (CNTs) have a well-defined nanostructure to exhibit high electrical conductivity and chemical stability, and have been used as an advanced material to make electrodes of super-capacitor. Graphene nanoribbons (GNRs), as manufactured by unzipping the CNTs, have more flexible adjustable electrical properties than CNTs, and are regarded an even more promising material for super-capacitor electrodes. This paper presented a series of attempts to prepare GNRs by chemically treating multi-walled carbon nanotubes (MWCNTs); this is, an Oxidation-Reduction method was tried to make GNRs by unzipping MWCNTs longitudinally. Efforts were made in various trials to find conditions …
Imaging the Local Density of States of Optical Corrals
2002
International audience; This paper reports the experimental observation, at optical frequencies, of the electromagnetic local density of states established by nanostructures corresponding to the recently introduced concept of optical corral [G. Colas des Francs et al., Phys. Rev. Lett. 86, 4950 (2001)]. The images obtained by a scanning near-field optical microscope under specific operational conditions are found in agreement with the theoretical maps of the optical local density of states. A clear functionality of detection by the scanning near-field optical microscope is thereby identified since the theoretical maps are computed without including any specific tip model.
A Novel Gas Sensor Transducer Based on Phthalocyanine Heterojunction Devices
2007
Abstract: Experimental data concerning the changes in the current-voltage (I-V) perfor-mances of a molecular material-based heterojunction consisting of hexadecafluorinated nickel phthalocyanine (Ni(F 16 Pc)) and nickel phthalocyanine (NiPc), (Au|Ni(F 16 Pc)|NiPc|Al) are introduced as an unprecedented principle of transduction for gas sensing performances. The respective n - and p -type doped-insulator behaviors of the respective materials are supported, owing to the observed changes in surface potential (using the Kelvin probe method) after submission to electron donor (ammonia) and electron acceptor gases (ozone). On the other hand, the bilayer device exhibits strong variations in the bui…
Lateral force microscopy of multiwalled carbon nanotubes
2009
Carbon nanotubes are usually imaged with the atomic force microscope (AFM) in non-contact mode. However, in many applications, such as mechanical manipulation or elasticity measurements, contact mode is used. The forces affecting the nanotube are then considerable and not fully understood. In this work lateral forces were measured during contact mode imaging with an AFM across a carbon nanotube. We found that, qualitatively, both magnitude and sign of the lateral forces to the AFM tip were independent of scan direction and can be concluded to arise from the tip slipping on the round edges of the nanotube. The dependence on the normal force applied to the tip and on the ratio between nanotub…
Cerium oxyhydroxide nanowire growth via electrogeneration of base in nonaqueous electrolytes
2008
The preparation of compact cerium oxyhydroxide nanowires into anodic alumina membranes from cerium chloride in ethanol solution via electrogeneration of base is reported. Scanning electron microscopy analyses indicate that dense, well-aligned, and highly ordered nanowires can be formed in a wide range of applied potentials and current densities in alcoholic solution. The employment of water brings to a hybrid nanotube/nanowire structure, suggesting a key role of the electrolyte nature in determining the morphology of the deposit. Electrochemical findings and X-ray diffraction analysis have shown that nanowires are constituted by a Ce(III)/Ce(IV) oxyhydroxide that can be completely oxidized …
Influence of electrodeposition techniques on Ni nanostructures
2008
Abstract Different Ni nanostructure arrays were fabricated by pulsed electrodeposition from a Watts bath inside the pores of anodic alumina membrane (AAM) templates. Under a trapezoidal waveform of potential, consisting of fast linear sweeps between 0 and −3 V (SCE) interleaved by delay times at 0 (10 s) and −3 V (0.1 s), Ni nanowires were grown. The rate of nanowires growth was constant up to 60 min of deposition. For longer times, the growth of nanowires was not uniform, and after about 180 min some nanowires reached the template surface exposed to the electrolyte. Under square potential pulses between the same potentials (pulse length 1 s), nanotubes of Ni are obtained. Morphological ana…
The fine structure of de-and reinnervated muscle spindles
1974
Reinnervated muscle spindles in lower lumbrical muscles of rats studied 17 days to 24 months after crushing the sciatic nerve showed a series of alterations which have not been analysed, thus far, by electron microscopy. There was a striking increase of the number of intrafusal muscle fibers seen in approximately 20% of reinnervated spindles. These spindles showed 5–11 intrafusal muscle fibers whereas normal spindles usually contained 3–4 fibers only.
Sur les Terminaisons Nerveuses Sensitives du Clitoris chez la Truie (Sus scrofa domesticus)
1991
Summary On the Sensory Nerve-Endings in the Porcine Clitoris Neural receptors of the porcine clitoris were examined using light and electron microscopy. Perfusion with ink allowed study of the unique vascular arrangement associated with the genital corpuscles. Sensory nerve-endings were generally rounded and formed a morphologically and structurally characteristic unit. They were composed of a network of primarily non-myelinated nerve fibers and flat cells. Between these structures, isolated small blood vessels were embedded amongst collagen fibers and amorphous material. An external capsule of variable thickness always surrounded the structures. A complex arrangement of vessels in the cent…