Characterization, film accuracy

In electrochemical grinding, the mechanical removal of both the passive anodic film and the metal proceeds concurrently with the anodic dissolution. In this method, normally electrolytes, in which the metal dissolution is localized only on the areas of abrasive depassivation, are used. This enhances the machining accuracy in relation to the ECM. As compared with mechanical grinding, the combined method is characterized by a significantly lower tool wear and a high productivity. 

Infrared Spectroscopy Infrared spectroscopy has been one of the most frequently used instrumental analysis methods to characterize qualitatively the surface functionalities in coals [224,225], carbon blacks [226], charcoals [227], activated carbons [80,228-233], activated carbon fibers [234,235], and carbon films [236,237]. Fourier analysis (FTIR) provides an improvement over dispersive IR spectroscopy in signal-to-noise (S/N) ratio, energy throughout, accuracy of the frequency scale, and a capacity for versatile data manipulation. 

Ellipsometry is an optical technique that detects the change of the polarization state when light is reflected from a surface. For rather simple systems like transparent films on reflecting substrates, film thickness and refractive index can be determined with high accuracy. More complicated samples (e.g., multilayer structures or layers with a graded index of refraction on a reflective carrier) can be characterized with a sufficient set of independent experimental data obtained for multiple angles of incidence and/or multiple wavelengths (spectroscopic ellipsometry). With a liquid cell, ellipsometry can be performed also in aqueous environments. 

Oxide Growth Kinetics and Mechanism. Formation of oxide films by potentiostatic polarization and their characterization by CV enables distinction of various oxide states as a function of the polarization conditions, here Ep, tp and T. This method allows precise determination of the thickness of oxide films with accuracy comparable to the most sensitive surface science techniques 4-7J1-20), CV may be considered the electrochemical analog of temperature programmed desorption, TPD, and one may refer to it as potential programmed desorption, PPD. Theoretical treatment of such determined oxide reduction charge densities by fitting of the data into oxide formation theories leads to derivation of important kinetic parameters of the process as a function of the polarization conditions. The kinetics of electro-oxidation of Rh at the ambient temperature were studied and some representative results are reported in ref 24. The present results are an extension of the previous experiments and they involve temperature dependence studies. 

The thickness determined from the ellipsometry measurements at various wavelengths should be the same if the measurements are made of the same interfacial system. Therefore, the accuracy of the determination can be checked. Films absorbing light k O) at certain frequency ranges can be studied at another range where it is completely transparent for unambiguous determination of the thickness. This in turn can be used in optical characterization at... 

In fact, X-ray Diffraction (XRD) is a powerful techniques used to uniquely identify the crystalline phases present in materials and to measure the structural properties of these phases. XRD offers unparalleled accuracy in the measurement of atomic spacing and is the technique of choice for determining strain states in thin films. XRD is non-contact and non-destructive, which makes it ideal for in situ studies. The intensities measured with XRD can provide quantitative and accurate information on the atomic arrangements at interfaces. Indeed, with lab-based equipment, surface sensitivities down to a thickness of 50 A are achievable, but synchrotron radiation allows the characterization of much thinner films and for many materials, monoatomic layers can be analyzed. 

For better understanding the diverse relaxation behavior of confined polymers, researchers have utilized models or simulation tools to capture the kinetic features of the material at the molecular level, aiming to represent the results observed in experiments. The FVHD model, which has been widely employed in characterizing physical aging in bulk polymers, is reformulated to describe the relaxation behavior of polymers under nanoconfinement. A dual mechanism combines the effect of vacancy diffusion and lattice contraction, and was recently applied with time-dependent internal length scales to characterize the free volume reduction in the aging process [169]. The dual mechanism model (DMM) fits the data of thin film permeability fairly well. The potential predictive capability of the DMM model depends on the accuracy of the relationship between the internal length and time scale on the description of complex material dynamics [161]. 

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