Iron silicides

After many attempts with several anode materials we found a stable anode. Silicon carbide and iron silicide, etc. in a conducting form are stable towards chlorine. The chlorine formed on the anode then reacts with the solvent (THF) forming chlorinated organic compounds. 

Therefore, we tried silicon carbide as the anode, which turned out to be completely stable against oxidation. Iron silicide and other silicides also seem to be stable. In our case, the reaction at the anode is the chlorination of the solvent. So, for instance, chlorinated products of THF can be detected by... 

Berzelius heated a mixture of silica, iron, and carbon to a very high temperature, and obtained iron silicide. When he decomposed this with hydrochloric acid, silica was precipitated, and the amount of hydrogen evolved was in excess of the iron, indicating that some other metal must have been present (9). Berzelius finally showed in 1824 that this other seemingly metallic substance was derived from the silica, and succeeded in preparing the amorphous form of it by two methods. In the first of... 

Iron(III) salts, and Grignard reagent reactivity, 9, 49 Iron seleno-terephthalates, for fungus and molds, 12, 458 Iron silicides, formation, 6, 19... 

K. Radermacher, S. Mantl, Ch. Dieker, H. Ltith, C. Freiburg. Growth kinetics of iron silicides fabricated by solid phase epitaxy or ion beam synthesis // Thin Solid Films.- 1992.-V.215, No.l.- P.76-81. 

A comparative study of microsilicas from 18 sources showed considerable variation in composition and properties, one of those examined containing as little as 23% of SiOj and having a specific surface area of only 7.5 m g (A21). The same study showed that in most of the samples the diffuse XRD peak from the glass accounted for 98-99.5% of the total diffracted intensity and that it peaked at the value of 0.405 nm characteristic of vitreous silica. The commonest crystalline impurities detected were KCl, quartz, metallic iron and iron silicide, and pozzolanic reactivity was found to depend more on the chemical composition and nature of impurities than on the fineness or SiOj content. A surface layer of carbon, if present, greatly decreased reactivity. 

Iron silicides are, in general, hard and brittle, thus forming good abrasives. They are white or grey in colour, and may take a good polish. Unattacked by air and water, they are but slowly decomposed by acids, except hydrofluoric, which readily dissolves them. In general their density falls with rise of silicon content. 

Iron silicide or Iron monosilidde, FeSi, is prepared by heating a mixture of copper silicide and iron filings in an electric furnace. The resulting product is treated with 50 per cent, nitric acid to decompose any copper silicide, and washed. Obtained in this way, iron silicide occurs as tetrahedral crystals, with a brilliant metallic lustre they are extremely hard, and have a density of 6-17 at 15° C. Fluorine attacks them at ordinary temperatures, whilst chlorine and bromine decompose them at red heat. Molten alkali hydroxides attack the silicide, as also do fused mixtures of the alkali nitrates and carbonates.11... 

Methods of obtaining the mixed silicides are described by Frilley, but these products generally contain iron silicide in considerable quantity. An aluminium tungsten silicide has also been described. ... 

NiZn, MnZn, CuZn, iron silicide, Ba0 Fe203, Sr0 6Fe203, Functionality none (Mn,Zn)y(Fe203)2-zn, BaPb, BaSrPb, Nd2Fei4B... 

NiZn Ferrite 72800, 72500 MnZn Ferrite 73300 CuZn Ferrite 126800 Iron silicide Fine, Corse Wright Industries, Inc., Brooklyn, NY, USA... 

The substrate was composed of a metal sheet and insulating layers which was coated on the both side of the metal sheet to be prevented fi om warping. Al-doped ferritic stainless steel (0.2 mm in thickness) was selected for the metal sheet. Because the value of liner thermal expansion coefficient of it (1.0 X10 K ) was in good agreement with that of iron silicide... 

Conductivity through disordered iron layers during its formation on Si(l 1 l)-7x7 and Si(l 11)-[(V3x i3)/30°]-Cr surface phase was investigated. Silicide formation on Si(l 11)7x7 surface is observed, but Si(U l)-( J3x 3)/30°-Cr surface phase behaves like a diffusion barrier for iron atoms. Nucleation and growth of iron islands proceeds with increasing of metal thickness without formation of iron silicide. Iron forms continuous two dimensional metal layer with near bulk parameters starting from the thickness of 1 nm. 

SiHg)x brownish substance. The dry material ignites spontaneously in air, leaving a SiOg residue which may be gray because of the presence of iron silicide. Evolves H 3with alkali hydroxides. 

An analysis of the iron silicide growth at small iron deposition rates (0.1-0.2 nm/min), small iron thicknesses (0.4-0.5 nm) and substrate temperature of 475 °C has shown that a formation of high-density (5-109-l-IO10 cm 2) nanosize p-FeSi2 islands (oblong of near round shape) is observed on both silicon surfaces. The surface between islands was not atomically smooth. This corresponds to destroy of atomically smooth surface between the silicide islands due to the strong silicon surface transport during silicide island formation. 

Silicon carbide behaves in various ways towards molten metals. It is not attacked by molten zinc or zinc vapor [199]. Molten aluminum attacks SiC slowly, forming AI4C3 and silicon, but as the silicon content increases, the reaction eventually ceases because an equilibrium is established [200]. Molten iron desolves SiC, forming iron carbide and iron silicide. 

Figure 7.5 A photograph of a sample of a product of combustion of ferrosilicon in nitrogen in a self-oscillation mode (longitudinal chip). Each light layer is enriched with silicon nitride each dark layer is enriched with iron silicides.

The nature of the bonds in the iron silicide FeSi and related crystals. Acta Cryst. 1 (1948) 212—216. (Linus Pauling and A. M. Soldate). 

Integration of a Peltier element can easily be done by depositing the materials of the two arms. Materials which have a good performance and which are compatible with Si-micromachining are polySi, SiGe and iron silicides [5,6]. 

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