<title>Amorphous diamond: a unique product of laser ablation</title>

Abstract

Composed of sp3 bonded nodules of carbon, amorphic diamond films are deposited in vacuum onto almost any substrate by condensing carbon ions carrying keV energies. These multiply charged ions are obtained from the laser ablation of graphite at intensities in excess of 1011 W cm-2. The high energy of condensation provides both for the chemical bonding of such films to a wide variety of substrates and for low values of residual compressive stress, 0.6 - 0.8 GPa. On selected films hardness cannot be measured because of deformation of the diamond indenter and only a lower limit of 78 GPa can be reported. Coatings of 2 - 5 micrometer thicknesses have extended lifetimes of materials such as Si, Ti, ZnS, ZnSe, Ge and stainless steel against the erosive wear from high-speed particles by factors of tens to thousands. The mechanical properties of amorphic diamond films are further enhanced by a low coefficient of friction of about 0.1. The combination of these mechanical properties seems to make amorphic diamond an attractive material for use as a protective coating in current industrial applications. Deposited upon silicon, quartz or sapphire, amorphic diamond films have interesting electrical properties including a very high coefficient of emissivity.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.