Thin-film deposition ultrathin

For ESs, FTIR is usually used with TEM, SEM, XRD, BET and other techniques to characterize electrode materials. For example, FTIR is used to examine and chemically confirm the presence of uniform ultrathin polymer layers formed on carbon nanofiber electrodes [52]. FTIR, SEM, and XRD are also used to study surface morphologies of materials, for example, surface changes created during activation of polyacrylonitrile thin films deposited on carbon fibers. Other examples include analysis of CNT electrodes after polyaniline... 

The developed sensor was used for ultrathin-film measurement. The reflection spectrum was shifted during the deposition of thin films (e.g., self-assembly of polyelectrolyte layers) onto the sensor end. The reflection between the thin film and the fiber endface was neglected because of their similar refractive indices. As the film increased its thickness, the length of the fiber cavity changed. The amount of change was estimated by the phase shift of the interferogram. The device could also be used as an immunosensor in which the optical thickness changes were used to... 

The structure of the so-called "composite" membranes used in reverse osmosis is also much more complex than the conventional, simplistic description of the ultrathin semipermeable film deposited on and supported by a porous substrate. Most of these membranes which exhibit high flux and separation are composed of an anisotropic, porous substrate topped by an anisotropic, ultrathin permselective dense layer which is either highly crosslinked, or exhibits a progressively decreased hydrophilicity toward the surface. The basic difference between the conventional anisotropic (asymmetric) membrane and the thin film composite is that the latter might be... 

Electrochemical behavior of ultrathin Pd epitaxial layers deposited electrochem-ically on Au(lll) and Au(lOO) has been found to be strongly dependent on the surface structures and the thickness of the Pd thin films [435]. From the kinetic studies of Pd deposition on Au(lll) electrode from K2 PdCU in 0.1 M H2 S O4, it has been deduced [436] that this process proceeds via an instantaneous nucleation and two-dimensional (2D) growth. Initial stages of Pd deposition on Au(llO) have also been studied by Robach et al. [437], who have applied STM, low-energy electron diffraction, and Auger electron spectroscopy for this purpose. 

When a very thin film (e.g., thicknesses of less than 1 pm) of a polymer is applied to a smooth surface of platinum, most polymers peel off within minutes upon immersion in liquid Lf20. This is also true for most plasma polymers applied to platinum surfaces. However, when an ultrathin film of CH4 LCVD was deposited under the conditions that provide plasma energy density sufficiently high to sputter aluminum from the electrodes, tenacious adhesion that survived over 10 h of boiling in saline solution was obtained, probably due to the incorporation of electrode metal at the interface. 

The most commonly used methods for the preparation of ultrathin oxide films are (1) direct oxidation of the parent metal surface, (2) preferential oxidation of one metal of choice from a suitable binary alloy, and (3) simultaneous deposition and oxidation of a metal on a refractory metal substrate. The detailed procedures for (1) and (2) are discussed elsewhere [7,56,57] procedure (3) is discussed here in detail. Preparation of a model thin-film oxide on a refractory metal substrate (such as Mo, Re, or Ta) is usually carried out by vapor-depositing the parent metal in an oxygen environment. These substrate refractory metals are typically cleaned by repeated cycles of Ar sputtering followed by high-temperature annealing and oxygen treatment. The choice of substrate is critical because film stoichiometry and crystallinity depend on lattice mismatch and other interfacial properties. Thin films of several oxides have been prepared in our laboratories and are discussed below. 

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