Reflectometry X-ray

These samples were measured non-destructively by energy-dispersive XRF with synclirotron radiation excitation (SYXRS), by g-XRF, by wavelength-dispersive XRF (WDXRS), and by Rutherford back scattering (RBS), by X-ray reflectometry (XRR) and by destructive secondary ion mass spectrometry (SIMS) as well (both last methods were used for independant comparison). 

X-ray reflectometry/ scattering (XR) X-rays X-rays 0.2 nm yes quantitative 0.1 nm mm roughness, composition profile... 

X-ray reflectometry (XR) has already been described in Sect. 2.1 as a technique for polymer surface investigations. If a suitable contrast between components is present buried interfaces may also be investigated (Fig. 4d) [44,61,62]. The contrast is determined by the difference in electron density between materials. It is, in the case of interfaces between polymers, only achieved if one component contains heavy atoms (chlorine, bromine, metals, etc.). Alternatively the location of the interface may be determined by the deposition of heavy markers at the interface. 

Structure of Thin Films and Plane Surfaces is studied in a grazing-incidence recipient by means of grazing incidence (GI) methods GISAXS, GIWAXS, or by X-ray reflectometry (XR). 

A number of methods are available for the characterization and examination of SAMs as well as for the observation of the reactions with the immobilized biomolecules. Only some of these methods are mentioned briefly here. These include surface plasmon resonance (SPR) [46], quartz crystal microbalance (QCM) [47,48], ellipsometry [12,49], contact angle measurement [50], infrared spectroscopy (FT-IR) [51,52], Raman spectroscopy [53], scanning tunneling microscopy (STM) [54], atomic force microscopy (AFM) [55,56], sum frequency spectroscopy. X-ray photoelectron spectroscopy (XPS) [57, 58], surface acoustic wave and acoustic plate mode devices, confocal imaging and optical microscopy, low-angle X-ray reflectometry, electrochemical methods [59] and Raster electron microscopy [60]. 

Lastly, Polystyrene (PS) brushes on silicate substrates were grafted via carbocationic polymerization from self-assembled monolayer (SAM) initiators as reported by Brittain et al The carbocationic initiators, 2-(4-(ll-triethoxysilylundecyl))phenyl-2-methoxypropane and 2-(4-trichlorosilyl-phenyl)-2-methoxy-d3-propane, and their corresponding SAMs were prepared on various substrates. The monolayers were characterized by FTIR-ATR, contact angles, and X-ray reflectometry. The growth of the PS brushes from... 

Figure 13.10 Structure of galactocerebroside (top) and result of an X-ray reflectometry experiment with galactocerebroside monolayer on water [605].

R. K. Thomas and J. Penfold, Neutron and X-ray Reflectometry of Interfacial Systems in Colloid and Polymer Chemistry, Curr. Opin. Coll. Interf Set, 1, 23 (1996). 

Due to the wave-particle duality of neutrons, they can be reflected and refracted in a manner similar to light. Reflected neutron beams can interfere with each other to produce a reflected beam intensity that is characteristic of the reflecting material (Lekner, 1987). Detailed analysis of the reflectivity is able to able to provide information on the structural organization normal to the surface on which the beam is incident. Neutron reflectometry is particularly useful (vis a vis x-ray reflectometry), since selective isotopic labeling can be used to highlight particular regions of interest in a surface structure. This is especially valuable for monolayers on surfaces. 

The thickness of the LBK film does not change under UV and blue light irradiation. This was confirmed by the X-ray experiments and has also been shown, by means of X-ray reflectometry, for 2,6 1 6,6 When the sample is... 

The structure with the deformed hairy rods is preserved when multilayers are deposited on solid supports, as evidenced by X ray reflectometry revealing a marked bilayered structure (see Figure 6.16). Photoisomeriza-tion of the a egated azobenzene chromophores in LBK films is possible and leads to significant structural changes. The bilayered structure is completely... 

The structure of self assembled monolayers terminated with phenol and 2-chlorophenol moieties was studied by reflectance FUR, X-ray reflectometry, solid state C NMR spectroscopy and measurements of contact angle with water. The pH values at half dissociation (pHi/2) of the monolayers were >12.5 and >12, respectively, which is at least 2.5 pH units higher than those of half dissociation of the corresponding phenols in solution, as denoted by their pXa values. The pH at which a certain contact angle was achieved was lower for the 2-chlorophenol moieties, in accordance with their higher acidity. ... 

Thermal expansion of thin (130-5 nm) PHOST films coated on various substrates has been measured by using specular X-ray reflectivity [487]. Complementary use of neutron and X-ray reflectometry has allowed one to measure the spatial evolution of the reaction front in the fBOC resist with nanometer resolution [499]. Using a bilayer geometry with a lower layer consisting of PHOST protected with COO(CD3)3 and an upper layer consisting of PHOST containing PAG, compositional and density depth profiles were measured. 

Mdbus, M. and Karl, N., The growth of organic thin films on silicon substrates studied by x-ray reflectometry. Thin Solid Films, 215, 213, 1992. 

Polymer materials find a wide application in replication technologies for producing structures with submicron elements of intricate shapes and for nano-scale surface replication [1-4]. They show considerable promise for smoothing out the surface roughness to obtain good-quality inexpensive substrates used in fabrication of X-ray optic components [5,6], In this work, the features of silicon wafer surface replication by polymers were studied by atomic-force microscopy (AFM) and X-ray reflectometry (XRR) with a view to applying this replication technique to produce smooth polymer-glass combination substrates to be used in multilayer X-ray mirrors. 

The existence of an evanescent wave was discussed above (cf. Section III), together with PSPs. The optical properties of thicker LBK films can be characterized by the optical waveguide spectroscopy (WGS), and their layered structure can be probed by means of X-ray reflectometry. 

For optical data storage, photosensitive hairy rod LBK structures can be constructed by incorporating photochromic molecules in the side chains [53-55]. The azobenzene molecules undergo transcis photoisomerization under irradiation of photoactive light with an appropriate wavelength, as detailed in the second section of this paper. This photochemical reaction has been shown to alter the structural properties of hairy rod LBK films, which have been investigated by using FT-IR and UV-VIS spectroscopies and X-ray reflectometry [54]. 

Kago K, Fuerst M, Matsuoka H, Yamaoka H, Seki T. 1999. Direct observation of photoisomerization of polymer monolayer on water surface by X ray reflectometry. Langmuir 15 2237 2240. 

With a different ferroelectric LC-polymer it was even possible to obtain very homogenous FS-films of thicknesses of only 6 to 16 layers as determined by both optical and X-ray reflectometry (5polymeric films contained a small fraction of polymerizable mesogenic side-groups, it was even possible to photocrosslink these systems. It should be mentioned that in this first case the crosslinking caused some changes in film morphology, but the resulting films are very stable and do not even break when small holes are formed by mechanical stress (JS),... 

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