Search results for "evaporation"

Role of Intrinsic Dipoles in the Evaporation‐Driven Assembly of Perovskite Nanocubes into Energy‐Harvesting Composites

2020

Fabrication and characterization of chromium based single-electron transistors with evaporated chromium oxide barrier tunnel junctions

1999

We fabricated chromium based single-electron transistors comprising small-area Cr/CrOx/Cr tunnel junctions with an evaporated chromium oxide barrier. The transistors are fabricated using e-beam lithography with a bilayer resist and two-angle shadow evaporation. We describe the fabrication process and discuss the device characteristics.

VAPORIZATION CHARACTERISTICS OF ETHANOL AND 1-PROPANOL DROPLETS AT HIGH TEMPERATURES

2012

International audience; A detailed description of the vaporization of an isolated droplet has been carried out in this experimental study aimed at investigating ethanol and another aliphatic alcohol, 1-propanol. The characterization of the vaporization phenomenon is necessary for this liquid fuel to develop efficient design of injection systems for propulsion and power generation. Particularly, the vaporization rates and their dependency on temperature, important features for modeling and design, are explored for both ethanol and 1-propanol at intermediate to high temperatures. The experimental setup consists of a pressure chamber in which the furnace, the droplet formation, the droplet sup…

Influence of the age of amorphous nonannealed As2S3 thin films on holographic properties

1998

The dependences of the maximal first order diffraction efficiency and the corresponding specific recording energy on the holographic grating period were studied. Grating period was varied from 0.40 to 70.0 μm. Both fresh and aged films were used. A large holographic recording efficiency decrease in the course of aging is found to take place. These changes are due to the effective film grain size increase caused by the relaxational structural changes and atmospheric oxygen exposure. Results are explained with the aid of stress fields induced by the evaporation and holographic recording. The obtained results can be used to optimize the hologram recording in amorphous chalcogenide films.

Interface thermodynamic model for low pressure evaporation

1979

Structural analysis of W3O/WO3 and TiO/TiO2 periodic multilayer thin films sputter deposited by the reactive gas pulsing process

2012

International audience; DC reactive sputtering was used to deposit titanium and tungsten-based metal/oxide periodic nanometric multilayers using pure metallic targets and Ar + O-2 gas mixture as reactive atmosphere. The innovative technique namely, the reactive gas pulsing process allows switching between the metal and oxide to prepare a periodic multilayered structure with various metalloid concentrations and nanometric dimensions. The same pulsing period was used for each deposition to produce metal-oxide periodic alternations close to 10 nm. Structure, crystallinity and chemical composition of these films were systematically investigated by Raman spectroscopy, X-ray diffraction and Energ…

Application of metal coatings for functionalization of technical fibers and fabrics

2011

The metal coatings in combination with sonochemical and leaching processes are used for nanostructuring and functionalization of glass, flax and hemp fabrics. The leaching is used for nanostructuring sodium alumosilicate K-glass fabrics to obtained silica like fibre with nanoporous structure on surface and in volume. The natural fibres as well as fabrics themselves are porous media. The porous media adsorbs water and content of moisture in fabrics have to be controlled. The metal-coated fabric characterization is an actual problem. Application of metal coatings for the functionalization of technical fibres and fabrics faced with influence of moisture on functional properties, e.g., the impe…

Tetrathiotetracene thin film morphology and electrical properties

2015

The electrical properties of organic thin films are determined by their chemical constituents and the morphology of the films deposited. In this paper the morphology of vacuum sublimed (7?10-6 mbar) tetrathiotetracene (TTT) thin films is shown to be strongly affected by the thermal deposition temperature (222-350 K) and rate of deposition. Mostly needle-like morphologies are identified by scanning electron microscopy. Optimal TTT purity (a pre-requisite for device preparation via subsequent oxidation) is evidenced by their initially low electrical conductivity. Altering the TTT morphology, by variation of the evaporation parameters, strongly affects this base electrical conductivity. Four p…

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons

2013

[EN] Molecular electronics based on structures ordered as neural networks emerges as the next evolutionary milestone in the construction of nanodevices with unprecedented applications. However, the straightforward formation of geometrically defined and interconnected nanostructures is crucial for the production of electronic circuitry nanoequivalents. Here we report on the molecularly fine-tuned self-assembly of tetrakis-Schiff base compounds into nanosized rings interconnected by unusually large nanorods providing a set of connections that mimic a biological network of neurons. The networks are produced through self-assembly resulting from the molecular conformation and noncovalent intermo…

"Smart" defects in colloidal photonic crystals

2005

AbstractWe present a bottom-up approach for the construction of "Smart" active defects in colloidal photonic crystals (CPCs). These structures incorporate polyelectrolyte multilayer (PEM) planar defects embedded in silica CPCs through a combination of evaporation induced self-assembly and microcontact transfer printing. We show how the enormous chemical diversity inherent to PEMs can be harnessed to create chemically active defect structures responsive to solvent vapor pressures, light, temperature as well as redox cycling. A sharp transmission state within the photonic stopband, induced by the PEM defect, can be precisely, reproducibly and in some cases reversibly tuned by these external s…