It is a long review on an established field of "diamond-like carbon" (DLC), which is an important coating material. It covers all its main aspects—growth, electronic properties, field emission, mechanical properties, bio—in contrast to other reviews.

Diamond-like carbon is amorphous carbon but with sp3 bonding (like in diamond) rather than sp2 bonding (like in graphite). But it is never 100% sp3. The dominance of sp3 bonding makes it chemically and physically inert so it is ideal for protective coatings, bio-coatings, etc. Its biggest use is coating disks and heads in computer hard disk drives. There has been a large effort to understand the growth mechanism and structure which is summarized. The minority sp2 component of the bonding determines the interesting electronic properties. Field emission was a strong motivation for work on DLC in the nineties, but this has now been superceded by using carbon nanotubes.

I have been doing it since 1984, and my last large review was in 1992, so it was time for another.

Professor John Robertson
Engineering Department
Cambridge University
Cambridge, UK