Silicides Subject

After aluminum, the refractory metals and their silicides have been the subject of the most extensive efforts in metal etching (150-155). Because the fluorides and chlorides of the transition metals and silicon are volatile in the presence of ion bombardment, etch studies have been performed with nearly... 

The silicon hydrides are prepd either by acid decompn of Mg silicide or by redn of SiCl4 with LiAlH4 (Refs 1-4, 12, 14,15, 16 26). Disilane and other higher hydrides have been conveniently synthesized by subjecting SiH4 to a silent electrical discharge (Ref 26, p 175). Prepn of individual silanes of ordn interest are given below... 

A method of producing the silicides by direct union has been described. The constituents are pressed into bars, and these are subjected to resistance heating. 

An interesting combination of incendiary actions is the subject of a German patent which claims thermitic high-temperature reactions between aluminum ( PyroschlifT ) or calcium silicide, with phosphates such as tertiary calcium phosphate as the oxidizer. Since phosphides are the products of reaction, the application of water during Are fighting will cause formation of self-flammable phosphine. It would appear that such secondary action might be more of a nuisance than tactically efficient. 

When zirconium silicate (ZrSi04) or a mixture of Z1O3 and SiOj is reacted with aluminum in the presence of aluminum oxide and then rdieated, zirconium silicide (ZrSi ) becomes the major product. Titanium dioxide (TiOs) and boron (111) oxide (BgO,) with aluminum similarly form titanium boride (TiBs). If the reduction of the oxides such as TiOg or Si02 with aluminum is performed in the presence of carbon black, the carbides TiC and SiC are formed embedded in aluminum oxide. This subject is also treated in a British patent titled Autothermic Fired Ceramics. ... 

The subject of this paper is the investigation of chlorine-containing nickel silicide phases. These are obtained by the reaction of silicon-rich phases with nickel(ll)chloride in evacuated ampoules during sufficiently long testing periods (Eq. 3). The compounds thus obtained have chlorine contents between 0.02 and 0.6 wt. %. In generally, the chlorine-containing silicides and their route of formation can be used as models to describe the catalytically active phases in the hydrodechlorination process [4],... 

Silicides based on Mo and Ti have been the subject of the greatest number of high-temperature oxidation studies and are treated in detail. Summaries of work on V5Si3, 3Si, and Fe and Ni silicides are then presented. 

A metal silicide is a compoimd that has silicon with more electropositive metal elements. Metal silicides have been the subject of numerous studies because of their potential applications in Si-based microelectronics and optoelectronics. They can be classified into two groups metallic and semiconducting silicides. Some metallic silicides (VsSi, NbaSi, CoSi2, etc.) are superconductors. Table 4.1 summarizes some physical properties of metallic silicides. 

Ceramics are crystalline in nature, with a dearth of free electrons. They have a high electrical resistivity, are very stable, chemically and thermally, and have a high melting point. They are formed by the bonding of a metal and a nonmetal and may exist as oxides, nitrides, carbides, or silicides. An exception is diamond, which consists of pure carbon subjected to high temperature and pressure. Diamond substrates meet the criteria for ceramics and may be considered as such in this context. 

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