Oxidation protective carbon layer for magnetic particles by surfactant reduction

Encapsulation of fine metal particles by graphite would not only provide an oxidation protective layer but also acts as a solid lubricant that enables high speed scanning of magnetic tapes against a writing/recording head. In this paper, we propose a novel method to produce the graphite layer on the surface of magnetic particles. First, the surfactant is adsorbed onto the particle and then reduced/decomposed by bombardment with ionized He atoms in the arc discharge chamber. As a result of this treatment, the magnetite particles are uniformly coated with a graphite layer of a few nanometers thick.