Boron diamond-like carbon

H. Nakazawa, A. Sudoh, M. Suemitsu, K. Yasui, T. ltoh,T. Endoh, Y. Narita, M. Mashita, Mechanical and tribological properties of boron, nitrogen-coincorporated diamond-like carbon films prepared by reactive radio-frequency magnetron sputtering., Diamond and Related Materials, vol. 19, pp. 503-506, 2010. 

Volume 1 starts with an introduction into novel ultra hard ceramics including diamond and diamond-like carbon, carbon nitrides and silicon nitrides as well as boron containing carbides, nitrides and carbonitrides. Here we wish to recognize the great fundamental and technological challenge of developing new superhard... 

While metallic solids are deposited by reactions that involve metallic intermediates and ionic solids result from ionic reactions, the solids with covalent bonds grow by means of radical surface reactions. Examples of such materials are diamond, amorphous diamond-like carbon, silicon, and silicon carbide. Diamond and diamond-like carbon can be deposited if hydrocarbon and hydrogen radicals are available at the growing surface. Silicon carbide and boron nitride growth has also been modeled in terms of radical reactions at the surface. 

Ternary materials that incorporate carbon into a boron-nitrogen framework are expected to exhibit extreme hardness as a result of their diamond-like structures. Alkyl-, vinyl- and alkynyl-substituted borazines are potential... 

PI5.9 Boron nitride (BN) is isoelectronic with carbon and the B, C, and N atoms are about the same size. The result is that BN forms crystal structures similar to those of carbon, in that it crystallizes in a hexagonal (graphite-like hBN) and a cubic (diamond like cBN) structure. The data summarized at the end of the problem are available for the two forms of BN.17... 

Boron as a dopant allows silicon and carbon materials to significantly change their conductivity and thereby open up applications in particular with boron-doped diamond (sp -carbon) as mechanically and chemically robust electrode material. The range of beneficial effects of boron in boron-doped diamond as electrode materiaP has been reported. Bio-electrochemical processes like the oxidation of NADH are possible with diamond dominating the interfacial chemistry. The sp nature of the diamond allows adsorption processes to be modified, and electrode erosion to be minimised, with electroanalytical application even under extreme conditions, for example in the presence of ultrasound and for pharmaceutical components. Boron surface functional groups have been reported to be crucial for electron transfer, for example, during glucose oxidation. ... 

Concerning the substrate, practically any material can be used to form a modified electrode, although the most used are gold, silver, platinum, mercury, and carbon (in its different variants, like glassy carbon, Highly Oriented Pyrolitic Graphite (HOPG), or Boron-Doped Diamond (BDD) electrodes [39]). 

Although the silicon atom has the same outer electronic structure as carbon its chemistry shows very little resemblance to that of carbon. It is true that elementary silicon has the same crystal structure as one of the forms of carbon (diamond) and that some of its simpler compounds have formulae like those of carbon compounds, but there is seldom much similarity in chemical or physical properties. Since it is more electro-positive than carbon it forms compounds with many metals which have typical alloy structures (see the silicides, p. 789) and some of these have the same structures as the corresponding borides. In fact, silicon in many ways resembles boron more closely than carbon, though the formulae of the compounds are usually quite different. Some of these resemblances are mentioned at the beginning of the next chapter. Silicides have few properties in common with carbides but many with borides, for example, the formation of extended networks of linked Si (B) atoms, though on the other hand few silicides are actually isostructural with borides because Si is appreciably larger than B and does not form some of the polyhedral complexes which are peculiar to boron and are one of the least understood features of boron chemistry. 

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