Multilayered systems

Flelfrioh W 1977 Sterio interaotion of fluid membranes in multilayer systems Z. Naturf. a 33 305... 

Thermal stahility. Yor applications of LB films, temperature stability is an important parameter. Different teclmiques have been employed to study tliis property for mono- and multilayers of arachidate LB films. In general, an increase in temperature is connected witli a confonnational disorder in tire films and above 390 K tire order present in tire films seems to vanish completely [45, 46 and 45] However, a comprehensive picture for order-disorder transitions in mono- and multilayer systems cannot be given. Nevertlieless, some general properties are found in all systems [47]. Gauche confonnations mostly reside at tire ends of tire chains at room temperature, but are also present inside tire... 

Mttltilayer Multilayer systems consist of series of radiation-reflecdive shields of low emittance separated by fillers or spacers of veiy low conductance and exposed to a high vacuum. 

Ellipsometry is a very powerfiil, simple, and totally nondestructive technique for determining optical constants, film thicknesses in multilayered systems, sur ce and... 

Fig. 3.38. HF-plasma SNMS sputter time profile (HFM) ofa multilayer system consisting of five double layers, 100 nm Si02 + 100 nm Si3N4, each, on a glass substrate (courtesy V.-D. Hodo-roaba, BAM Berlin, and Schott Glas, Mainz, Germany).

Recent applications of e-beam and HF-plasma SNMS have been published in the following areas aerosol particles [3.77], X-ray mirrors [3.78, 3.79], ceramics and hard coatings [3.80-3.84], glasses [3.85], interface reactions [3.86], ion implantations [3.87], molecular beam epitaxy (MBE) layers [3.88], multilayer systems [3.89], ohmic contacts [3.90], organic additives [3.91], perovskite-type and superconducting layers [3.92], steel [3.93, 3.94], surface deposition [3.95], sub-surface diffusion [3.96], sensors [3.97-3.99], soil [3.100], and thermal barrier coatings [3.101]. 

As an example of a multilayer system we reproduce, in Fig. 3, experimental TPD spectra of Cs/Ru(0001) [34,35] and theoretical spectra [36] calculated from Eq. (4) with 6, T) calculated by the transfer matrix method with M = 6 on a hexagonal lattice. In the lattice gas Hamiltonian we have short-ranged repulsions in the first layer to reproduce the (V X a/3) and p 2 x 2) structures in addition to a long-ranged mean field repulsion. Second and third layers have attractive interactions to account for condensation in layer-by-layer growth. The calculations not only successfully account for the gross features of the TPD spectra but also explain a subtle feature of delayed desorption between third and second layers. As well, the lattice gas parameters obtained by this fit reproduce the bulk sublimation energy of cesium in the third layer. 

In addition, there are some multilayer systems without epitaxial growth, consisting of crystal/amorphous constituents, amorphous/amorphous constituents, such as TiN/CNx... 

In conclusion, one should choose an appropriate multilayer system for different application purposes. For the case of fatigue wear, multilayer films consisting of two hard materials with different shear modulus, such as DLCAVC multilayer film [115], would satisfy the requirement for wear resistance. While for abrasive wear, multilayer films consisting of hard ceramic layers and soft metal layers, such as TiN/Ti and CrN/Cr [116,117] multilayer films are more competent. 

Multilayer coatings or hlms have been proven to be successful in various applications, especially for wear protection. In multilayer systems, the intrinsic stress can be effectively reduced by designing interface number and composite materials in terms of the application and process technique. Therefore, the multilayer technique by which a specihe functional composite is able to approach received more attention for many years [17,18]. Here we introduce the results on microscale friction and scratch of DLC/DLC and Fe-N/TiN multilayers. 

Fig. 7.83 Mossbauer transmission spectra of Au/Fe multilayer systems with varying Au-layer thickness, measured at 16 K and fitted by a four-component model, including magnetic hyperfine interaction at the Au layer atoms (from [437])...

XANES spectroscopy is also the basis of chemically sensitive X-ray imaging, as well as qualitative and quantitative microspectroscopy [306], ptXANES is attractive for chemical analysis, with its spatial resolution down to 10 ptm. Variations on the theme are surface EXAFS (SEXAFS), grazing incidence XAS and in situ time-resolved XAS investigations. Grazing angle XAFS can be used for the study of ultrathin multilayer systems. 

The design of cover systems is site-specific and depends on the intended function of the final cover—components can range from a single-layer system to a complex multilayer system. To minimize percolation, conventional cover systems use low-permeability barrier layers. These barrier layers are often constructed of compacted clay, geomembranes, geosynthetic clay liners, or combinations of these materials. 

When investigating opaque or transparent samples, where the laser light can penetrate the surface and be scattered into deeper regions, Raman light from these deeper zones also contributes to the collected signal and is of particular relevance with non-homogeneous samples, e.g., multilayer systems or blends. The above equation is only valid, if the beam is focused on the sample surface. Different considerations apply to confocal Raman spectroscopy, which is a very useful technique to probe (depth profile) samples below their surface. This nondestructive method is appropriate for studies on thin layers, inclusions and impurities buried within a matrix, and will be discussed below. 

It has been known for a long time that solar UV irradiation is the greatest danger for unprotected spores. A multilayer system with an aluminium covering, and containing added protective materials such as glucose (up to 10-4 M), had clear protective properties. The high resistance of the Bacillus subtilis spores is probably due to two effects ... 

Polerecky L., Hamrle J., MacCraith B.D., Theory of the radiation of dipoles placed within a multilayer system, Appl Opt. 2000 39 3968-3977. 

Diy EVOH/PP-g-maleic mldehyde (MAH) blend, obtained by moulded injection also evidenced good barrier properties for toluene. This property is improved by increasing EVOH concentration which determines both size and deformation of the minor phase increase, indicating that the laminar structure becomes more pronounced [296], But even the laminar structure is maximized a moulded injection sample is not likely to reach a permeability as low as expected for a multilayered system [296],... 

In other white light devices, blue, green and red emitters are combined. Kido et al. [169, 170] designed multilayer systems using 6 (TPD) for blue, metal-chelate complexes for green and red emission, respectively. Similar devices have been developed by other groups, using Forster transfer or exciton confinement for the creation of the three primary colors [171, 172]. Exciplex emission was... 

In actual experiments in biophysics, the interface may not be a simple interface between two media, but rather a stratified multilayer system. One example is the case of a biological membrane or lipid bilayer interposed between glass and aqueous media. Another example is a thin metal film coating, which quenches fluorescence within the first 10 nm of the surface... 

The unique ability of these LbL redox multilayer systems with control of film thickness on the nanometer scale, the composition and thickness of each alternate layer separately as well as the surface charge by choice of the topmost layer brings about design and tailored properties of devices with important applications. 

X-ray diffraction patterns of electrodeposited multilayered systems of sufficiently good quality to allow quantitative analysis of coherent and noncoherent strain features. 

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