Surface modification of magnetic recording heads by plasma immersion ion implantation and deposition

Abstract

Plasma immersion ion implantation and deposition is a novel process for surface modification. By combining plasma deposition and ion implantation and using filtered vacuum arc plasmas, thin film formation, direct and recoil ion implantation, and ion-beam-assisted intermixing of the film and substrate can be accomplished simultaneously. The implications of this technique in tribology of magnetic recording media have been investigated experimentally. Surfaces of Al2O3-TiC heads were modified with silver, carbon, and titanium ions at doses of 3×1016 ions/cm2 and mean implantation energies between 2.0 and 4.2 keV. Simulation results indicated that the modified regions exhibited high concentrations of implanted species in the top 2-3 nm, atomically mixed interfaces, and thicknesses between 10 and 25 nm. Surface imaging with an atomic force microscope and nanoindentation testing revealed that the modified heads possessed smoother topographies and increased hardnesses. Contact start-stop and continuous sliding experiments with modified heads and carbon-coated magnetic rigid disks and microscopy observations demonstrated that significant enhancement of the friction and wear characteristics can be achieved with the present surface modification technique. The possible reasons for the improved tribological behavior and the predominant mechanisms during contact start-stop and continuous sliding are interpreted in light of the obtained experimental results.