Arsenic arsenide

As arsenic >As—, arsanetriyl arsenic arsenide (general) As3-, arsenide(3—), arsanetriide arsenide arsenido (general) As3-, arsanetriido arsenido... 

M.p. — 116-3 C, b.p. —55°C. An unstable poisonous gas (metal arsenide plus acid or arsenic compounds plus Zn plus dil. acid, AsCla plus LiAlH4) which decomposes to As... 

If antimony and arsenic are present ia the feed, copper and iron react to form the respective antimonides and arsenides known as speiss (specific gravity 6.0). If it is preferred to remove copper ia a speiss layer, the sulfur ia the siater must be reduced and the addition of scrap iron may be necessary to encourage speiss formation. Matte and speiss are usually sent to a copper smelter for recovery of the metals. 

Lead—antimony or lead—arsenic ahoys must not be mixed with lead—calcium (aluminum) ahoys in the molten state. Addition of lead—calcium—aluminum ahoys to lead—antimony ahoys results in reaction of calcium or aluminum with the antimony and arsenic to form arsenides and antimonides. The dross containing the arsenides and antimonides floats to the surface of the molten lead ahoy and may generate poisonous arsine or stibine if it becomes wet. Care must be taken to prevent mixing of calcium and antimony ahoys and to ensure proper handling of drosses. 

Elemental arsenic combines with many metals to form arsenides. When heated in the presence of halogens it forms trihaUdes however, pentahaUdes with the exception of AsF (2) and the unstable AsQ. are not readily formed. It reacts with sulfur to form the compounds AS2S2, AsS, As2S, and complex mixtures in various proportions (see Arsenic compounds). 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Arsine is used for the preparation of gallium arsenide [1303-00-0] GaAs, (17), and there are numerous patents covering this subject (see Arsenic and ARSENIC alloys). The conversion of a monomeric arsinogaHane to gallium arsenide has also been described (18). GaUium arsenide has important appHcations in the field of optoelectronic and microwave devices (see Lasers Microwave technology Photodetectors). 

Other Arsenic Hydrides. Diarsine [15942-63-9] AS2H4, occurs as a by-product in the preparation of arsine by treatment of a magnesium aluminum arsenide alloy with dilute sulfuric acid and also may be prepared by passing arsine at low pressure through an ozonizer-type discharge tube (19). Diarsine is fairly stable as a gas but quite unstable (above — 100°C) in condensed phases. The for diarsine is +117 4 kJ/mol (28 1 kcal/mol) and... 

In the U ansport of gallium arsenide by chlorine, there is a competition between the monochloride and the nichloride for the uansport of gallium after arsenic has evaporated as the element or as a chloride. The probability... 

Arsenic exists as grey, yellow and black forms of differing physical properties and susceptibilities towards atmospheric oxygen. The general chemistry is similar to that of phosphorus but whereas phosphorus is non-metallic, the common form of arsenic is metallic. Traces of arsenides may be present in metallic residues and drosses these may yield highly toxic arsine, ASH3, with water. 

S. Muthuvenkatranian, S. Gorantla, R. Venkat, D. L. Dorsey. Theoretical study of antisite arsenic incorporation in the low temperature molecular beam epitaxy of gallium arsenide. J App Phys S5 5845, 1998. 

Arsen-saure, /, arsenic acid, -silber, n, silver arsenide, -silberblende,/, proustite, -spiegel, m. arsenic mirror, -suifid, n, arsenic sulfide, esp. the pentasulfide. -sulfur, n. arsenic trisulfide, arsenic(III) sulfide, -iir, n, (-ous) arsenide, -verbindung, /. arsenic compound, -vergiftung, /. arsenic poisoning, -wasser-stoff, m. arsenic hydride, arseniuretted hydrogen (specif, arsine, AsHa). -zink, n. zinc arsenide. 

Blei, n. lead, -abgang, m. lead dross, lead scoria, -ablagerung,/. lead deposit, -acetat, n. lead acetate, -ader, /. lead vein, -anti-monerz, n., -antimonglanz, m. zinkenite. -arbeit, /. lead smelting plumbing, -arse-nat, n. lead arsenate, -arsenglanz, m. sarto-rite. -arsenik, m. lead arsenate lead arsenide, -art, /. kind or variety of lead. 

Gallium arsenide is a semiconducting material. If we wish to modify the sample by replacing a small amount of the arsenic with an element to produce an n-type semiconductor, which element would we choose selenium, phosphorus, or silicon Why ... 

Arsenic and antimony are metalloids. They have been known in the pure state since ancient times because they are easily obtained from their ores (Fig. 15.3). In the elemental state, they are used primarily in the semiconductor industry and in the lead alloys used as electrodes in storage batteries. Gallium arsenide is used in lasers, including the lasers used in CD players. Metallic bismuth, with its large, weakly bonded atoms, has a low melting point and is used in alloys that serve as fire detectors in sprinkler systems the alloy melts when a fire breaks out nearby, and the sprinkler system is activated. Like ice, solid bismuth is less dense than the liquid. As a result, molten bismuth does not shrink when it solidifies in molds, and so it is used to make low-temperature castings. 

The radii in the lowest row of the table were obtained by a number of approximate considerations. For instance, if we assume the bismuth radius to bear the same ratio to the interatomic distance in elementary bismuth as in the case of arsenic and antimony, we obtain (Bi) = 1.16— 1.47 A. A similar conclusion is reached from a study of NiSb and NiBi (with the nickel arsenide structure). Although the structures of the aurous halides have not been determined, it may be pointed out that if they are assumed to be tetrahedral (B3 or Bi) the interatomic distances in the chloride, bromide, and iodide calculated from the observed densities1) are 2.52, 2.66, and 2.75 A, to be compared with 2.19, 2.66, and 2.78 A, respectively, from pur table. 

Most of these compounds were originally prepared by liquid-phase epitaxy. That process is now largely replaced by MOCVD, particularly in the case of gallium arsenide, gallium arsenic phosphide, and gallium aluminum phosphide. 

LED materials include gallium arsenic phosphide, gallium aluminum arsenide, gallium phosphide, gallium indium phosphide, and gallium aluminum phosphide. The preferred deposition process is MOCVD, which permits very exacting control of the epitaxial growth and purity. Typical applications of LED s are watches, clocks, scales, calculators, computers, optical transmission devices, and many others. 

The first alkali metal-niobium-arsenic compounds were synthesized by accident while attempting the synthesis of alkali-metal main-group arsenides at relatively high temperature. It turns out that niobium and tantalum containers react readily... 

---