Nitrogen metal carbides

Chlorine Ammonia, acetylene, alcohols, alkanes, benzene, butadiene, carbon disulflde, dibutyl phthalate, ethers, fluorine, glycerol, hydrocarbons, hydrogen, sodium carbide, flnely divided metals, metal acetylides and carbides, nitrogen compounds, nonmetals, nonmetal hydrides, phosphorus compounds, polychlorobi-phenyl, silicones, steel, sulfldes, synthetic rubber, turpentine... 

See Hydrogen chloride Metal acetylides or carbides Nitrogen oxide... 

Why do carbides and nitrides exhibit the properties that make them so useful in industrial applications It is well accepted that these properties are related to the strength of interatomic bonding.2 In transition metal carbides and nitrides, bonding is believed to have both covalent and ionic contributions.3 The carbon or nitrogen atoms occupy interstitial sites in the metal lattice and are believed to promote strong metal-to-nonmetal and metal-to-metal bonds.1 More detailed bonding explanations require... 

The present study made use of diffusion couples where metals were reacted with carbon or nitrogen with the purpose of determining both phase equilibria and nonmetal diffusivities for Group 4 and 5 transition metal carbide and nitride systems. 

A new method of interpreting Auger electron spectroscopy (AES) sputter profiles of transition metal carbides and nitrides is proposed. It is shown that the chemical information hidden in the shape of the peaks, and usually neglected in depth profiles, can be successfully extracted by factor analysis (FA). The various carbide and nitride phases of model samples were separated by application of FA to the spectra recorded during AES depth profiles. The different chemical states of carbon, nitrogen and metal were clearly identified. 

See Tungsten carbide Nitrogen oxides Ditungsten carbide Oxidants See Other NON-METAL OXIDES, OXIDANTS... 

To make calcium cyanamide, atmospheric nitrogen can be fixed by the Frank-Caro or Cyanamide process. This process is based on the fact that metallic carbides, particularly calcium carbide, readily react with nitrogen to form the metal cyanamide. In the first step of this process lime and carbon are heated to produce calcium carbide. Then fairly pure nitrogen reacts with the calcium carbide to form calcium cyanamide ... 

Tungsten carbide — WC, belongs to a class of Group IV B-VIB transition metal carbides and nitrides, often referred to as interstitial alloys, in which the carbon and nitrogen atoms occupy the interstitial lattice positions of the metal [i]. These compounds possess properties known from group VIII B precious metals like platinum and palladium [ii]. Thus, they show remarkable catalytic activities, attributed to a distinct electronic structure induced by the presence of carbon or nitrogen in the metal lattice. Tungsten carbide resembles platinum in its electrocatalytic oxidation activity (- electrocatalysis) and is therefore often considered as an inexpensive anode electrocatalyst for fuel cell [iii] and -> biofuel cell [iv] application. 

Because of the evident structmal similarities between transition metal carbides and transition metal nitrides the carbon atoms in group 4 and 5 carbides can be replaced completely by nitrogen without changing the structme of the binary phases. So far only one distinct ternary phase Cr2 (C,N)2 has been reported. Intersolubihty between the binary nitrides and carbides in the group 6 carbonitride systems Cr-C-N and Mo-C-N is not complete because of the differences in the crystal structmes of the carbide and nitride phases. 

Interestingly, the transition metal carbides and nitrides do not show the expected decrease in heat conductivities with temperature but instead an increase. Figure 10 illustrates this property for the group 4 nitrides and shows a comparison with group 4 carbides and carbonitrides. The substitution of nitrogen by carbon in group 4 transition metal nitrides significantly reduces the heat conductivities. 

In crystal structure the metallic carbides and nitrides are almost all interstitial compounds in which the carbon or nitrogen atoms are found in the octahedral interstices of the metal lattice. The borides and silicides as well as a few carbides (e.g. Cr3C2) possess more complex structures. 

Metal acetylides or carbides Mellor. 1946. Vol. 5, 849 Caesimn acetylide ignites at lOO C in the gas. See Tungsten carbide Nitrogen oxides... 

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