Hydriding chemical vapor deposition

Saita et al. [80] applied hydriding chemical vapor deposition (HCVD) for preparing MgH. They used commercial Mg, which was heated to 600°C and vaporized in a hydrogen atmosphere at a pressure of 4 MPa. The reaction product was deposited on a cooled Inconel substrate and subsequently collected for further investigation. Quite remarkably, the obtained morphology was nanofibrous, as shown in Fig. 2.47, and is very similar to the one fabricated by Zlotea et al. [79]. Each fiber was less than 1 jm in diameter and 10 or more micrometers in length. 

Saita, T. Toshima, S. Tanada, T. AMyama, Hydrogen storage property of MgH synthesized by hydriding chemical vapor deposition, J. Alloys Compd. 446-447 (2007) 80- 3. 

MOCVD (metal-organic chemical vapor deposition), OMVPE (organometallic vapor-phase epitaxy), and HVPE (hydride vapor-phase epitaxy) have some... 

Similar to chemical vapor deposition, reactants or precursors for chemical vapor synthesis are volatile metal-organics, carbonyls, hydrides, chlorides, etc. delivered to the hot-wall reactor as a vapor. A typical laboratory reactor consists of a precursor delivery system, a reaction zone, a particle collector, and a pumping system. Modification of the precursor delivery system and the reaction zone allows synthesis of pure oxide, doped oxide, or multi-component nanoparticles. For example, copper nanoparticles can be prepared from copper acetylacetone complexes [70], while europium doped yttiria can be obtained from their organometallic precursors [71]. 

The trimethylamine adduct of aluminum hydride (alane) has been of recent interest as a precursor for the chemical vapor deposition (CVD) of aluminum metal1 and aluminum gallium arsenide thin films.2 Because of the absence of aluminum-carbon covalent bonds in the precursor, carbon incorporation in the resulting films can be suppressed significantly. In addition, the deposition temperature can be lowered. 

In chemical vapor deposition (CVD) reactive vapor precursors react to produce solid materials in the gas phase or at the solid-gas interface on the substrate surface at appropriate temperatures. Typical precursors used in the CVD process are metal hydrides, metal chlorides, and metal organic compounds. In the case that the precursor species are metal organic compounds, the process is called metal-organic chemical vapor deposition (MOCVD). The precursor molecules are introduced into a reactor sometimes with a carrier gas and decompose by means of heat, irradiation of UV light, or electrical plasma formed in the gas. Thermal CVD is the most commonly used method. This technique has an advantage that refractory materials can be vapour-deposited at relatively low temperatures,... 

A method that overcomes some of these limitations is metal-organic chemical vapor deposition (MOCVD), sometimes called organometallic vapor phase epitaxy (OMVPE) °. An organometallic compound such as a group IIB alkyl reacts with a chalcogenide hydride on a substrate that is at the highest temperature in the chamber ... 

Altogether easier of access, more stable, and more tractable are complexes in which AIH3 is coordinated by one or more base molecules, e.g., (MegNl AlHs (n = 1 or 2). These are of interest as hydride sources for hydroalumination of unsaturated substrates 10, 140), as precursors to the hydrides of other metals, and, as already noted, in the chemical vapor deposition of aluminum metal in thin-film technology (21-26). The 1 1 trimethylamine adduct, MesN-AlHs, is monomeric in the vapor but, in common with PhCH2Me2N-AlH3 and... 

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