Cation deficiency

Titanium Nitride. Titanium nitride [25583-20-4] has the cubic NaCl stmeture, but the stmeture is stable over a wide range of either anion or cation deficiency (TINq 25 = 421 pm TiN q, = 423.5 pm). The nitride is a better conductor of electricity than titanium metal. It becomes... 

McLT78 McLarnen, T. J. The combinatorics of cation-deficient close-packed structures. J. Solid State Chem. 26 (1978) 235-244. 

In transport-limited conditions, however, susceptibility is not so important due to the isolating effect of thick soils. In the extreme situation of a flat landscape lowering at a uniform rate, the erosional contribution by a particular rock type should be related only to the area exposed. Solids would be cation-deficient. 

Electrochemical studies were carried out in the above cation-deficient thiospi-nel. The cyclic voltammogram of Cu5.5SiFe4Sni2S32 in 1 M LiBF4 electrolyte between 1 and 4.6 V versus the Li/Li electrode is given in Fig 15.6. However, no clear peaks could be observed in the CV plot. 

There is a decrease in (Cu-S) bond length from 2.320 A in the parent compound, Cu8Fe4Sni2S32, to 2.312 A in the cation-deficient compound studied here. On the other hand the Fe/Sn-S distances increase slightly from 2.536 A in the former to 2.5419 A in the cation-deficient sample. This effect may be due to the presence of vacancies in 8 a sites which increases the covalent character of the Fe/Sn-S bond. 

These studies show that the thiospinel structure is quite flexible with opportunity for cation vacancies at the 8 a site. Our investigation on such cation-deficient thiospinels is significant in that it shows that additional vacancies are possible in the 8 a site. Most of the cation-deficient compounds known earlier (predominantly copper compounds) were obtained by extraction of Cu by using various oxidizing reagents. These studies show that such cation-deficient quaternary thiospinels can also be obtained by direct solid-state reactions. 

Extensive structural, optical, and electronic studies on the chalcopyrite semiconductors have been stimulated by the promising photovoltaic and photoelectrochem-ical properties of the copper-indium diselenide, CuInSe2, having a direct gap of about 1.0 eV, viz. close to optimal for terrestrial photovoltaics, and a high absorption coefficient which exceeds 10 cm . The physical properties of this and the other compounds of the family can be modulated to some extent by a slight deviation from stoichiometry. Thus, both anion and cation deficiencies may be tolerated, inducing, respectively, n- and p-type conductivities a p-type behavior would associate to either selenium excess or copper deficiency. 

Figure 13. Energy difference between the 5-(Mn)tet-(Subz)oct04 spinel and r5-(Mn5Uib2)oct04 cation-deficient rock-salt structures.

Maghemite, y-Fe203, is a red-brown, ferrimagnetic mineral isostructural with magnetite, but with cation deficient sites. It occurs in soils as a weathering product of... 

A stable, cation-deficient phase written as Fei xO (with 1-x ranging from 0.83 to 0.95) exists at 0.1 MPa pressure and temperatures greater than 567 °C. This phase... 

Pt(II) compound reactivation, 37 201 Pt(IV) compound reduction, 37 201 rate-determining step, 37 199-201 tetrachloride, 4 187-188 tetracyanide anions, as one-dimensional electrical conductors, 26 235-268 anion-deficient structures anhydrous compounds, 26 252-254 dimerization, 26 249-251 hydrated derivatives, 26 245-252 physics, 26 260-263 with potassium bromide, 26 248-249 with rubidium chloride, 26 249-250 cation-deficient compounds, 26 244, 254-256... 

The metallic character of the cation-deficient partially oxidized tetracyano-platinate complexes is of considerable interest because of their unusual anisotropic electrical properties. The method used in the preparation of these compounds is a modification of the procedure used by Levy1 and gives a higher yield of pure product than the syntheses previously described in the literature2 5 (only the potassium compound has been reported to date). 

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