Nickel selenide

Bina Selenides. Most biaary selenides are formed by beating selenium ia the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts ia aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH 2S [66455-76-3]. Atmospheric oxygen oxidizes the selenides more rapidly than the corresponding sulfides and more slowly than the teUurides. Selenides of the alkah, alkaline-earth metals, and lanthanum elements are water soluble and readily hydrolyzed. Heavy-metal selenides are iasoluble ia water. Polyselenides form when selenium reacts with alkah metals dissolved ia hquid ammonia. Metal (M) hydrogen selenides of the M HSe type are known. Some heavy-metal selenides show important and useful electric, photoelectric, photo-optical, and semiconductor properties. Ferroselenium and nickel selenide are made by sintering a mixture of selenium and metal powder. 

Nickel(II) sulfide, NiS (millerite) nickel(II, III) sulfide, NisSa (polymidite) nickel(III) sulfide, Ni3S2 nickel sulfide, Ni3S2 (heazelwoodite) nickel sulfide, NiS2 (vaesite) nickel selenide, NiSc2 nickel(II) selenide, NiSe nickel telluride, NiTc2 (melonite). 

Nickel selenide, 22 87 Nickel-selenium, 22 73t Nickel sensitization, 17 119 Nickel silicate, 17 89 Nickel silicate green olivine, formula and DCMA number, 7 347t Nickel silicides, 17 121 uses for, 17 123 Nickel-silver, 7 759... 

Aluminium and magnesium selenides are very similar light brown powders, unstable in air. Zinc and iron (ferrous) selenides are more stable in air, the zinc compound being citron-yellow and the iron compound black and metallic in appearance.8 The latter becomes brown in air owing to oxidation. Ferric selenide is difficult to obtain pure. Cadmium selenide, which is dark brown, is very stable in colour and is used as a pigment. With thallium, selenium is said to form three distinct compounds,9 but analyses of these compounds have led to discordant results. The selenides of aluminium, chromium and uranium cannot be prepared in the wet way. Nickel selenide, unlike the sulphide, shows no tendency to form a colloidal solution. 

Nickel Monoselenide or Nickel Selenide, NiSe, results in regular double tetrahedra when nickel is exposed at dull red heat to vaporised selenium diluted with nitrogen. It is also obtained by the action of hydrogen selenide upon anhydrous nickel chloride at bright red heat.7 It is greyish blue in colour. Density 8-46. 

SYNS NICKEL SELENIDE NICKEL SELENIDE (3 2) CRYSTALLINE... 

Gronvold, F., Fligh-temperature reaction calorimeter. Enthalpy of formation of iron selenides and nickel selenides at 1050 K, Acta Chem. Scand, 26, (1972), 2085-2099. Cited on pages 311, 325, 326, 327. 

Another example of a modifier used to stabilize the analyte is the use of nickel nitrate in the determination of selenium in biological tissues. Addition of nickel nitrate as a modifier retains Se in the furnace as nickel selenide while allowing the pyrolysis and removal of the organic matrix. Without the addition of nickel nitrate, the pyrolysis temperature must be 350°C or less to prevent loss of Se. With the use of nickel nitrate, temperatures up to 1100°C can be used. 

Nickel is often used as matrix modifier in the determinations of arsenic and selenium. Nickel stabilizes arsenic up to about 1700 K, and selenium up to about 1500 K. This is presumably due to the formation of thermally stable nickel arsenide and nickel selenide. Nickel can also be used to stabilize bismuth, antimony, and tellurium. In addition, copper, silver, molybdenum, palladium, and platinum salts have been proposed as stabilizers for these elements. Palladium and platinum are the most suitable matrix modifiers for both inorganically and organically bound tellurium. Pretreatment temperatures up to 1320 K can be used. The effect of different matrix modifiers on the determination of antimony are shown in Figure 74. Without matrix modifiers the losses of antimony begin at 1000 K. Palladium, molybdenum, and nickel are the most suitable to stabilize antimony and with these modifiers pretreatment temperatures up to about 1600 K can be used. 

Fig. 15 Morphology characterization of the as-prepared sample 1 (a) overall view (b-d) SEM images at different magnifications of nickel selenide nanodandelion arrays. Reproduced from ref. 146 with permission from the Royal Society of Chemistry.

Thin films of tellurides CdTe, Sb2Tc3, or In2Tc3 have been obtained by CVD techniques from compounds such as (12.397). A recent report describes the use of the single source precursor (12.397c) for obtaining thin films of nickel phosphide and nickel selenide [10]. 

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