Salt silicon nitrides

The Badische AniKn- und Soda-Fabrik prepared a nitride of undetermined composition by heating a mixture of silica and carbon in an atm. of nitrogen. The reaction proceeds at a relatively low temp, if a hydroxide or salt of a metal be added. The product contains silicon nitride mixed with the nitride of the metal. The Badische Anilin- und Soda-Fabrik also removed many of the impurities—iron, carbon, silicates, carbides, silicides, and phosphides—by treatment with acids or mild oxidizing agents which do not affect the silicon nitride. A. S. Larsen and O. J. Storm prepared the nitride by the action of nitrogen on molten silicides—e.g. ferrosilicon. 

Some ceramic materials are not found widely or at all in nature, and thus are synthesized for use. To prepare more complex ceramic compositions such as perovskites of general structural formula ABO3, and ferrites, of formula MFc204, the individual oxides or salts of the cations A, B, and M are often combined as powders and then reacted at high temperature by a solid-state diffusion mechanism. Silicon nitride (Si3N4) can be manufactured from either the nitridation of silicon metal or from the reaction of silicon tetrachloride with ammonia. Silicon carbide (SiC) is obtained from the reduction of silica with a carbon containing source. 

LITHIUM NITRIDE (26134-62-3) Dust or powder ignites spontaneously in moist air. Contact with water or steam forms lithium hydroxide and ammonia. A strong reducing agent. Violent reaction with many materials, including oxidizers, carbon tetrachloride, 2,4-dinitrophenol, epoxides, metal salts, silicon tetrafluoride. Incompatible with copper chloride. In case of fire, use approved Class D extinguishers or smothering quantities of dry sand, crushed limestone, clay. 

Amorphous silicon nitride films, which are resistant to water vapor, salts, and other chemicals and, therefore, are applied as a final encapsulating layer for ICs, are effectively produced using PECVD. A typical feed-gas mixture for PECVD is SiH4-NH3. The process is performed in plasma at pressures of 0.25-3 Torr conventional substrate temperatures are in the range 250-500°C. Deposition rates of silicon nitride films under such conditions are about 20-50 nm/min. The plasma deposited silicon nitride film can usually be characterized... 

The morphological pattern of the products of silicon vapor combustion in gaseous nitrogen at condensation synthesis with skeleton crystal formation as well as denchite growth of silicon nitride crystals in melted metal salts proves the existence of the nonequilibrium mechanism of structure formation in the case of SHS. The mechanism appears to be the basis of the conception of nanodispersed particle formation under the combustion mode [28]. 

Silicon was determined by a classical analytical technique in which the initial dissolution of the sample was achieved by alkali salt fusion. The results are typical for silicon nitride powders and confirm the applicability of this technique to the quantitative determination of silicon in silicon nitride. 

HM>9) Gray amorphous powder or crystals. Corrosion-resistant to molten metals such as Al, Pb, Zn, Cd, Bi, Rb, and Sn, and molten salts NaCl-KCl, NaF, and sihcate glasses. Corroded by molten Mg, Ti, V, Cr, Fe, Co, cryolite, KOH, and NaaO. Silicon nitride (Nitrasil )... 

Density is 1.9 to 2.3 kg/1 and flexural strength 30 to 90 mPa. Silicon oxynitride is used as a lining for cells for the electrolysis of AICI3 to A1 and ZnCl2 to Zn, and as crucibles and tubes for molten salts. It occurs as a constituent of nitride bonds (see silicon nitride, SILICON carbide) and has been used to strengthen silica optical fibres by surface coating. 

Examples of eq. (6.14) include the roasting of metal sulfides the absorption of sulfur dioxide by calcium oxide that is formed by simultaneous calcination of limestone the formation of silicon nitride from silica, carbon and nitrogen. Examples of eq. (6.15) the baking of clay the burning of limestone the pyrolysis of coal, lignite, wood, peat, or other organic materials the calcination of sodium bicarbonate and similar salts. 

Boron nitride is one of the most outstanding corrosion-resistant materials. It is inert to gasoline, benzene, alcohol, acetone, chlorinated hydrocarbons and other organic solvents. It is not wetted by molten aluminum, copper, cadmium, iron, antimony, bismuth, silicon, germanium, nor by many molten salts and glasses. It is used extensively as crucible material, particularly for molten metals, glasses and ceramic processing. 

Metallic contamination is mainly present on the wafer surface as adsorbed ions, oxides, hydroxides and salts. These species are generally instantaneously dissolved in acidic media, even in weak acids such as HF or citric acid. Furthermore HF-based chemistries are able to remove the contamination diffused into silicon oxides or nitrides by lift-off mechanism [23] even faster than a conventional SC2 [1]. 

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