Diamond Properties : Surface Properties

The diamond surfaces are probably some of the most widely studied surfaces of a solid [1, 2].Basic science and the search for optimal conditions that allow synthesis of good qualitydiamond films at high deposition rate have motivated efforts to elucidate the properties ofthe surfaces of these materials.

Presently, the combination of experimental and theoreticalwork has begun to shed light on the characteristics of diamond surfaces [3–15]. Diamond hasthree prominent low-index faces: (100), (111) and (110).

• the (100) surface reconstructs intoan energetically favourable (2×1) structure, while
• the (111) substrate exhibits the Pandey-chain configuration [3–6, 12–15].
• the (110) face which is found to be the most rapidlygrowing phase during chemical vapour deposition (CVD) growth assumes a stable (1×1)configuration [3, 14, 15].

Despite all these efforts, little is known about the structure of the surface near a step.In reality, the diamond surface is rough and found to contain steps which were discoveredto considerably affect the behaviour of the diamond surface at elevated temperature duringCVD growth [16–19].

Diamond repels water, an unusual property for a mineral. Diamond's strong bonding and carbon composition cause its surface to repel water but to readily accept wax and grease. These two properties provide an effective means of separating diamonds from other minerals that come out of mining operations.

Washed gravel containing diamonds is flushed with water over a sloping surface covered with a mixture of wax and grease, a "grease table." The diamonds stick to the table, while the wetted waste minerals wash over it. Gem diamonds readily pick up a greasy film, but cleaning with ammonia or a good detergent restores their brilliance.

Other Properties of Diamond.