Nanorings promise big memory

Researchers are always looking for better memory.

There are many projects aimed at making computer memory that holds more information in smaller spaces, memory that allows data to be retrieved more quickly, and memory that does not have to be refreshed so often. Today's computers use dynamic random access memory, which must be constantly refreshed, and therefore requires a constant stream of electricity in order to retain information.

Researchers from Purdue University and the University of Cambridge in England have found a way to cause magnetic cobalt nanoparticles to spontaneously assemble into rings that are less than 100 nanometers across -- or about one-tenth the diameter an E. coli bacterium.

Each ring contains a magnetic field that can flow either clockwise or counter-clockwise. The two directions can represent the 1s and 0s of computer information. Because the molecule is small, memory made from it could hold a great deal information. And because the rings work magnetically, they would not need power to retain information.

The magnetic fields are stable at room temperature. Also, unlike most magnets, each ring keeps its magnetic field to itself, which is also a good attribute for stable memory.

The method could be used to produce practical magnetic random-access memory in 10 to 20 years, according to the researchers. The work appeared in the November 3, 2003 issue of Angewandte Chemie International Edition.