Subject arsenides

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). 

Tri-copper Arsenide, CusAs, has been prepared by melting a mixture of copper and arsenic under a layer of fused boric acid 8 by subjecting an intimate mixture of the elements in the required proportions to a pressure of 6500 atm. 9 by heating copper in arsenic vapour 10 by... 

Tri-copper Di-arsenide, Cu3As2, is formed when arsine acts on a solution of copper sulphate,17 or on dry copper sulphate or chloride 18 by subjecting a suitable mixture of the powdered elements to a pressure of 6500 atm. 19 by reducing cupric arsenite with fused potassium... 

When subjected to high pressure certain phosphides and arsenides of metals of Groups IIIB and IVB adopt either the cubic NaCl structure (InP, InAs) or a tetragonal variant of this structure (GeP, GeAs) shown in Fig. 6.1(c) in which there are bonds of three different lengths and effectively 5-coordination. The compounds of Ge and Sn, with a total of nine valence electrons, are metallic conductors. This property is not a characteristic only of the distorted NaCl structure, for SnP forms both the cubic and tetragonal structures, and both polymorphs exhibit metallic conduction. (IC 1970 9 335 JSSC 1970 1 143.)... 

Chemical.—It is neutral in reaction. In contact with air and moisture its H is slowly removed by oxidation, and elementary As deposited. It is also decomposed into its elements by the passage through it of luminous electric discharges and when subjected to a red heat. It is acted on by dry O at ordinary temperatures with the formation of a black deposit which is at first solid hydrogen arsenid, later elementary As. A mixture of AsHa and 0, containing 3 vols. O and 2 vols. AsHs, explodes when heated, forming AsjOs and HjO. If the proportion of O be less, elementary As is deposited. 

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