A New Generation of Magnetic Medium for Improved Information Storage Devices

A new generation of information (magnetic) storage medium is being proposed in the form of carbon nanotubes infiltrated with a ferro-magnetic material core. By virtue of their acicular shape and small size (2-20 nm diameter and 50-200 nm in length), such carbon nanotubes with a magnetic material core will be an excellent alternative to the current state-of-the-art information storage materials such as acicular micron-sized particulates of Fe2O3, Co-adsorbed Fe2O3, -Fe with a surface passivation layer of Fe2O3 or CrO2. It is expected that the acicular shape will retain the anisotropy of magnetization while the order-of-magnitude reduction in the scale of these particulates will permit a tremendous increase in information storage density. Further, the carbon nanotubes being non-ferromagnetic, will serve as a natural barrier between individual magnetic domains which will improve the signal response. In addition to the above, the encapsulation of the ferro-magnetic material inside the carbon tube may exhibit some benefits with respect to decreased head wear while the reduction in the magnetic material particulate size should also result in decreased surface roughness which is one of the contributing factors to tape noise. It is proposed to infiltrate these carbon nanotubes either in-situ (during their synthesis) or after synthesis using vapor infiltration etc.) with Fe-group materials since they exhibit high coercivity. The success of such a program will have an impact as a dual-use technology.