Deposition chemical vapor technique

Figure 1 shows a segment of the FTIR absorbance spectrum of a thin film of the oxide of silicon deposited by chemical vapor deposition techniques. In this film, sil-... 

Stinton, D., Besmann, T., andLowden, R., Advanced Ceramics by Chemical Vapor Deposition Techniques, Ceram. Bui, 67(2) 350-355(1988)... 

The GRADEIS listed are named for the usage to which they are applied, and are usually minimum purities required for the particular application. Fiber optic materials are currently prepared by chemical vapor deposition techniques because any handling of materials introduces impurities. 

The synthesis of MNCGs can be obtained by sol-gel, sputtering, chemical vapor-deposition techniques. Ion implantation of metal or semiconductor ions into glass has been explored since the last decade as a useful technique to produce nanocomposite materials in which nanometer sized metal or semiconductor particles are embedded in dielectric matrices [1,2,4,23-29]. Furthermore, ion implantation has been used as the first step of combined methodologies that involve other treatments such as thermal annealing in controlled atmosphere, laser, or ion irradiation [30-32]. 

Plasma CVD Plasma chemical vapor deposition. Technique for synthesizing materials in which chemical components in vapor phase excited by plasma react to form a solid film at some surface. 

Meng G, Song H, Dong Q, and Peng D. Application of novel aerosol-assisted chemical vapor deposition techniques for SOFC thin films. Solid State Ionics 2004 175 29-34. 

Evaporative decomposition erf solutions and spary pyrolysis have been found to be useful in the preparation of submicrometer oxide and non-oxide particles, including high temperature superconducting ceramics [819, 820], Allowing uniform aerosol droplets (titanium ethoxide in ethanol, for example) to react with a vapor (water, for example) to produce spherical colloidal particles with controllable sizes and size distributions [821-825] is an alternative vapor phase approach. Chemical vapor deposition techniques (CVD) have also been extended to the formation of ceramic particles [825]. 

Despite the kinetic lability of the Ln-X-cr-bonds (even the thermodynamically very stable Ln-OR bond is subject to rapid ligand exchange reactions [49]) organolanthanide compounds are thermally very robust over a wide range of temperature (Fig. 5) [114, 116, 139, 144-151]. Thermal stability is not only favorable in catalytic transformations at elevated temperatures [47], for the support of volatile molecular precursors is of fundamental importance in chemical vapor deposition techniques the sublimation behavior is a criterion of thermal stability and suitability for these processes (Fig. 5). 

Atomic layer deposition, also known as atomic layer epitaxy (Suntola and Antson, 1977), is a chemical vapor deposition technique capable of producing extremely thin uniform films (Ritala and Leskela, 2001 Leskela and Ritala, 2003). The method differs from conventional chemical vapor deposition in that the precursors, of which there are typically two, are not exposed to the substrate simultaneously. Rather, the first precursor is introduced into the reaction chamber, where it binds to the substrate at complete monolayer coverage a Langmuir... 

Organometallic complexes are used as precursors for thin films generated by chemical vapor deposition techniques. Supported organotransition metal complexes can serve as both models for film growth and as precursors to films and other materials. 

In many studies the separation factor, which is indicative of the membrane s ability to separate two gases in a mixture, is predominantly governed by Knudsen diffusion. Knudsen diffusion is useful in gas separation mostly when two gases are significantly different in their molecular weights. In other cases, more effective uansport mechanisms are required. The pore size of the membrane needs to be smaller so that molecular sieving effects become operative. Some new membrane materials such as zeolites and other molecular sieve materials and membrane modifications by the sol-gel and chemical vapor deposition techniques are all in the horizon. Alternatively, it is desirable to tailor the gas-membrane interaction for promoting such transport mechanisms as surface diffusion or capillary condensation. 

Boron-doped diamond (BDD) thin films were synthesized at CSEM (Neuchatel, Switzerland) by the hot filament chemical vapor deposition technique (HF CVD) on p-type, low-resistivity (l-3mQcm), single-crystal, silicon wafers (Siltronix). The temperature of the filament was between 2440 and 2560 °C and that of the substrate was monitored at 830 °C. The reactive gas was a mixture of 1% methane in hydrogen, containing trimethylboron as a boron source (1-3 ppm, with respect to H2). The reaction chamber was supplied with the gas mixture at a flow rate of 51 min giving a growth rate of 0.24 pm h for the diamond layer. The obtained diamond film has a thickness of about 1 pm ( 10%) and a resistivity of 15mQcm ( 30%). This HF CVD process produces columnar, random textured, polycrystalline films [9]. 

In the fifteen years since publication of the first edition of Comprehensive Coordination Chemistry (CCC, 1987), group 5 chemistry has been part of the intensive development of ceramic, optical, and magnetic materials based upon metal borides, nitrides, phosphides, oxides, and sulfides. A major impetus came from the discovery of the high-temperature superconducting oxides. In addition, the search for new routes to these materials via sol-gel or chemical vapor deposition techniques has spurred growth in metal amido, oxo, alkoxo, thio, and carboxylato chemistry. 

Nanoscale materials are those with dimensions less than 100 nm. Most of the nanomaterials used, such as oxides, sulfides, nitrides, and others are well known, in many cases since the beginning of civilization. In recent decades, it has been observed that specific properties of these materials, useful in biomedical, electromagnetic, mechanical, and catalytic areas," can be enhanced by reducing particle size to nanoscale dimensions. Many synthetic strategies have been developed in order to obtain nanometric materials with specific properties. Thin films of powders, in particular, have been the subject of current investigations. Studies of new synthetic approaches for nanometric films are intimately connected with the development of the chemical vapor deposition technique, which has widespread acceptance and is used for the production of important supplies for semiconductor electronic applications. ... 

These expensive carbon-carbon fiber composites are used for thermally demanding applications like aircraft and racecar brakes. Typically, both pads and rotors are made of carbon composite. These friction couples have a relatively low friction level, which is insensitive to the high temperatures experienced in operation. Friction couple components are expensive to manufacture as they are fabricated by time-consuming chemical vapor deposition techniques. Carbon-carbon systems suffer from low cold friction and are best suited for hot operation. 

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