Nickel nitride

Nickel Nitride, Ni2N (or Ni4N2), has been obtained 8 by heating reduced nickel in a current of ammonia at about 500° C. It is also formed when nickelamide, Ni(NH2)2, is heated at 120° C. in a vacuum.9 Nickel nitride is a black powder, readily soluble in dilute hydrochloric or sulphuric acid, and completely decomposed when heated in hydrogen, its nitrogen being evolved as ammonia.10... 

Only two nickel nitrides have been studied with diffraction techniques. Ni3N crystallizes with hexagonal eutaxy of the Ni atoms the N atoms fill 1/3 of the octahedral holes [348] and is isostructural with e-Fe3N. Ni4N has the antiperovskite structure [349]. 

Ultrapredsion Grinding, Fig. 3 Finish of titanium-nickel-nitride coated steel obtained with oil and water-based coolant... 

The late-transition metals (Group VII and VIII) either do not form nitrides at all, such as the precious metals, or else form nitrides with intennediate (distorted) interstitial structures. These materials decompose readily and are not chemically stable. Examples are manganese, iron, cobalt, and nickel nitrides. In this respect, they are similar to the intermediate carbides (see Ch. 2, Sec. 6.3). 

A more extensive comparison of many potential turbine blade materials is available (67). The refractory metals and a ceramic, sHicon nitride, provide a much higher value of 100 h stress—mpture life, normalised by density, than any of the cobalt- or nickel-base aHoys. Several intermetaHics and intermetaUic matrix composites, eg, aHoyed Nb Al and MoSi —SiC composites, also show very high creep resistance at 1100°C (68). Nevertheless, the superaHoys are expected to continue to dominate high temperature aHoy technology for some time. 

Phosphides. Compounds of phosphoms containing the more electropositive elements are generally called phosphides. A large number of binary phosphides as well as many ternary mixed-metal phosphides, metal phosphide nitrides, etc, are known. Some binary phosphides, such as those of nickel, exhibit a variety of stoichiometries (Ni P, Ni P2, Nq2P5, Ni2P, Ni P, NiP, NiP2, NiP ), whereas others, such as aluminum, form only one (AlP). Metalloids such as B and Si also form phosphides. 

The methods of choice for beryUium oxide in beryUium metal are inert gas fusion and fast neutron activation. In the inert gas fusion technique, the sample is fused with nickel metal in a graphite cmcible under a stream of helium or argon. BeryUium oxide is reduced, and the evolved carbon monoxide is measured by infrared absorption spectrometry. BeryUium nitride decomposes under the same fusion conditions and may be determined by measurement of the evolved nitrogen. Oxygen may also be determined by activation with 14 MeV neutrons (20). The only significant interferents in the neutron activation technique are fluorine and boron, which are seldom encountered in beryUium metal samples. 

The greatest use of cubic boron nitride is as an abrasive under the name Bora2on, in the form of small crystals, 1—500 p.m in si2e. Usually these crystals are incorporated in abrasive wheels and used to grind hard ferrous and nickel-based alloys, ranging from high speed steel tools and chilled cast-iron to gas turbine parts. The extreme hardness of the crystals and their resistance to attack by air and hot metal make the wheels very durable, and close tolerances can be maintained on the workpieces. 

Device materials again may be conductive, semiconductive, dielectric, or resistive. Conductors are typically gold or aluminum, and resistors, sHicon monoxide or sHicon nitride. Tantalum nitride and nickel chromium are common resistor materials. 

Such binary borides (p. 145), carbides (p. 297) and nitrides (p. 417) as are formed have been referred to already. The ability of the metals to absorb molecular hydrogen has also been alluded to above. While the existence of definite hydrides of nickel and platinum is in doubt the... 

Iron Nitrides as Fischer-Tropsch Catalysts Robert B. Anderson Hydrogenation of Organic Compounds with Synthesis Gas Milton Orchin The Uses of Raney Nickel Eugene Lieber and Fred L. Morritz... 

Ni3C decomposition is included in this class on the basis of Doremieux s conclusion [669] that the slow step is the combination of carbon atoms on reactant surfaces. The reaction (543—613 K) obeyed first-order [eqn. (15)] kinetics. The rate was not significantly different in nitrogen and, unlike the hydrides and nitrides, the mobile lattice constituent was not volatilized but deposited as amorphous carbon. The mechanism suggested is that carbon diffuses from within the structure to a surface where combination occurs. When carbon concentration within the crystal has been decreased sufficiently, nuclei of nickel metal are formed and thereafter reaction proceeds through boundary displacement. 

Newton s second law, L0 nickel, 49, 665 nickel arsenide structure, 201 nickel surface, 189 nickel tetracarbonyl, 665 nickel-metal hydride cell, 520 NiMH cell, 520 nitrate ion, 69, 99 nitration, 745 nitric acid, 629 nitric oxide, 73, 629 oxidation, 549 nitride, 627 nitriding, 208 nitrite ion, 102 nitrogen, 120, 624 bonding in, 108 configuration, 35 photoelectron spectrum, 120... 

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