Boron compounds arsenides

Boron compounds with nonmetals, i.e., boron hydrides, carbides, nitrides, oxides, silicides, and arsenides, show simple atomic structures. For example, boron nitride (BN) can be found in layered hexagonal, rhombohedral, and turbostratic or denser cubic and wurtzite-like structures, as well as in the form of nanotubes and fullerenes. Boron compounds with metalloids also differ from borides by electronic properties being semiconductors or wide-gap insulators. 

Arsenic does not combine directly with carbon, silicon or boron. The reaction with metals to form definite arsenides or alloys is described no pp. 57-78. The presence of small quantities of arsenic or of its compounds in certain catalysts has a poisoning effect. The first traces added to the catalyst have the greatest effect thus the activity of 0-35 g. of platinum was reduced linearly by the addition of arsenic up to 0-7 mg., this quantity reducing the catalytic activity to 45 per cent, of its original value the addition of 10 mg. of arsenic, however, depressed the activity only to 26 per cent, of the original value.3 Vanadium catalysts are poisoned by the presence of arsenic, although the action is slow arsenic pentoxide is formed.4... 

Generally speaking most of the shallow impurity levels which we shall encounter are based on substitution by an impurity atom for one of the host atoms. An atom must also occupy an interstitial site to be a shallow impurity. In fact, interstitial lithium in silicon has been reported to act as a shallow donor level. All of the impurities associated with shallow impurity levels are not always located at the substitutional sites, but a part of the impurities are at interstitial sites. Indeed, about 90% of group-VA elements and boron implanted into Si almost certainly take up substitutional sites i.e., they replace atoms of the host lattice, but the remaining atoms of 10% are at interstitial sites. About 30% of the implanted atoms of group-IIIA elements except boron are located at either a substitutional site or an interstitial site, and the other 40% atoms exist at unspecified sites in Si [3]. The location of the impurity atoms in the semiconductors substitutional, interstitial, or other site, is a matter of considerable concern to us, because the electric property depends on whether they are at the substitutional, interstitial, or other sites. The number of possible impurity configurations is doubled when we consider even substitutional impurities in a compound semiconductor such as ZnO and gallium arsenide instead of an elemental semiconductor such as Si [4],... 

There are no published values of the heats of atomization of boron and aluminum phosphides, arsenides, and antimonides. The published enthalpies of formation of the other A B compounds are often highly contradictory. Because of this, we estimated the enthalpies of formation of all A B semiconducting compounds by subtracting the heats of vaporization of the components of a given compound from the heat of atomization of this compound. The latter was found by summing the heats of atomization of the corresponding elemental semiconductors (Table 1). The results of such calculations are presented in Table 3. 

---