Thin Films and Coatings

XPS has been used in almost every area in which the properties of surfaces are important. The most prominent areas can be deduced from conferences on surface analysis, especially from ECASIA, which is held every two years. These areas are adhesion, biomaterials, catalysis, ceramics and glasses, corrosion, environmental problems, magnetic materials, metals, micro- and optoelectronics, nanomaterials, polymers and composite materials, superconductors, thin films and coatings, and tribology and wear. The contributions to these conferences are also representative of actual surface-analytical problems and studies [2.33 a,b]. A few examples from the areas mentioned above are given below more comprehensive discussions of the applications of XPS are given elsewhere [1.1,1.3-1.9, 2.34—2.39]. 

This method is very important in the preparation of high-purity thin films and coatings it consists in the decomposition of gaseous species (the precursor molecules) and the consequent deposition of the products on a suitable object. The decomposition in the gas phase may be induced by heat or, for instance, by irradiation. The precursor may be a simple molecule, as in the deposition of an element (for instance Si or Ge) from their hydrides, or a mixture of different molecules (Cr from CrCl2 + H2 Si02 from Si(CH2CH3)4 + 02 of air GaAs as described in 6.12). 

P. Zeng, Y. B. Yin, M. Bilek and D. McKenzie, 2nd International Conference on Advances of Thin Films and Coating Technology, Singapore, 2004, p. 202... 

It is of interest primarily for very uniform ultra-thin films and coatings (0.002-5 mils) in applications such as electrical resistors, thermistors, thermocouples, stator cores, connectors, fast-sensing probes, photo cells, memory units, dropwise steam condensers for recovery of sea water, pellicles for beam splitters in optical instruments, windows for nuclear radiation counters, panels for micrometeorite detection, dielectric supports for planar capacitors, encapsulation of reactive powders, and supports in x-ray and optical work. Any significant growth would depend upon a major breakthrough in process techniques and a consequent lowering in price. 

Chemical vapor deposition. Chemical vapor deposition is mainly used to prepare thin films and coatings, and infrequently, supported particles.68,69 The films are formed by the chemical reaction of a gas phase species with the heated surface of a substrate. The process can be assisted by a reactive gas like NH3, a plasma,7a 72 ultraviolet73,74 or laser75 radiation. 

From the above mentioned silica preparation paths, the sol-gel route is the most studied and consequently most documented. Sol-gel processing is used not only for the preparation of silica gels, but also for the synthesis of ceramic products, ranging from thin films and coatings over porous membranes to composite bodies.4... 

The use of thin films and coatings obtained by Chemical Vapor Deposition (CVD) expands continuously. Nowadays it includes rather different technological applications such as tribological applications, microelectronics or biotechnologies. 

Diamond, which is the hardest known material, is a natural choice for tribological application. In fact, this has been one of the major motivating factors to develop the synthesis of this unique allotrope of carbon in the thin film form. Today, diamond thin films and coatings are considered to be technologically important to a wide variety of applications due to their remarkable combination of extreme properties. 

Differential calorimetry has been applied to the study of rapid photopolymerizations. This new technique holds great promise for basic and applied research on photopolymerization and other photochemical reactions. The method requires only a few milligrams of sample, can be used on network-forming systems, and can approximate actual conditions of thin film and coating technologies. 

Preparation of Solid State Electrolytes 17.3.7.S. Zircronia-Based Ceramic Electrolytes. 17.3.7.3.3. Thin Films and Coatings. 

Thin films and coatings can be fabricated by vapor deposition [i.e., chemical vapor deposition (CVD) and electrochemical vapor deposition (EVD)], sputtering, sol-gel processing, and electrophoretic depositionElectrochemical vapor deposition, a thin-film technique, is used to form thin ( 40 pm) layers of dense yttria-stabilized zirconia in the seal-less tubular solid oxide fuel celP ". Thin layers of stabilized zirconia are required in this application to keep the internal resistance and the operating temperature of the electrochemical device as low as possible. 

This book contains papers from the Fourth International Conference on Computational Methods and Experiments in Materials Characterisation which brought researchers who use computational methods, those who perform experiments, and of course those who do both, in all areas of materials characterisation, to discuss their recent results and ideas, in order to foster the multidisciplinary approach that has become necessary for the study of complex phenomena. The papers in the book cover the follow topics Advances in Composites Ceramics and Advanced Materials Alloys Cements Biomaterials Thin Films and Coatings Imaging and Image Analysis Thermal Analysis New Methods Surface Chemistry Nano Materials Damage Mechanics Fatigue and Fracture Innovative Computational Techniques Computational Models and Experiments Mechanical Characterisation and Testing. 

However, comparative data on identical tests can be used to predict performance in many thin film and coating applications. 

The first application of a quartz crystal for use as a nonisothermal thermobalance was reported by Henderson ei al. (66). This was accomplished through the use of a minicomputer to characterize the temperature-frequency relationship for the crystal and to correct numerically the frequency-temperature-mass relationship to obtain the TG curve of the sample. One advantage of such a system is that very fast heating rates may be employed due to small sample size (t-40 jug typical) and high sensitivity. Thin films of sample exhibit rapid gas diffusion and thus permit thermal equilibrium to be maintained at heating rates of l00°C/min or greater. Applications of this thermobalance include the evaluation of thin films and coatings as well as various polymer studies of pyrolysis, flammability, and so on. 

Thin films and coatings that sustain the release of DNA from surfaces could play an important role in the development of localized approaches to gene therapy... 

For thin films and coated fabrics it is common to use a measure of mass per unit area rather than density. A test piece of given dimensions is cut and weighed, as for example in... 

Optical thin films and coatings Edited by A. Piegari and E Flory... 

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