Recording studies on a self-assembling medium of cobalt nano-particles

The potential of a rugged recording medium derived from precursor films of cobalt nitride that on rapid thermal processing disassociate and reassemble into a dispersion of nanoscale (∼10 nm dia.) cobalt particles is critically evaluated against commercial thin-film media exhibiting similar coercivity. Extensive low-velocity contact recording experiments show the medium capable of supporting linear densities in excess of 160 kfci (T-50 point) but that unacceptable levels of predominantly transition noise currently mar this performance. The source of this problem is identified as an excessive particle packing density resulting in weak interparticle interactions. Magnetic force imaging on small areas of recorded data shows evidence of particle-particle interactions and this is confirmed to be prevalent across the medium by analysis of ΔI plots derived from isothermal remnant magnetisation and DC demagnetisation curves taken using conventional magnetometry. Suggestions for resolving the high particle density are presented.