Hot tip boosts disk capacity

Many research efforts are aimed at increasing the amount of information that can be stored in a given area of magnetic media like computer disks. One challenge is making smaller magnetic bits that are stable at room temperature.

One possibility is switching to different recording media whose bits, or recording areas, remain stable at smaller sizes than those of materials currently in use. The flip side of stability is writeability, however -- these materials are more difficult to change.

Scientists at IBM Research have demonstrated a relatively inexpensive way to use heat to make it easier to write magnetic patterns on such media. The technique could make it possible to store more than one terabit per square inch, according to the researchers. That's nearly 27 DVDs worth of information. The technique would also be relatively fast -- recording speeds of more than one billion bits per second, or gigahertz, are possible, according to the researchers.

Key to the researchers' method is a heated tip mounted on a minuscule cantilever. Other approaches to heat-assisted magnetic data storage use more expensive lasers. The researchers' prototype achieved magnetization patterns capable of storing 400 gigabits per square inch.

The technique could be used practically in five to ten years, according to the researchers. The work appeared in the February 2, 2004 issue of Applied Physics Letters.