A Magnet the Size of a Molecule

June 18, 2003

By Murray Tong
SPARK Program

Prof. Kathryn Preuss is studying new ways to make miniature magnets for use in computers and storage media.
Photo by Olivia Brown

Move over, notebook computers: U of G researchers are studying new ways to make miniature magnets - the size of a molecule, in fact - that could render chunky computer circuits and storage media obsolete.

Prof. Kathryn Preuss, Chemistry and Biochemistry, and her research team are looking at molecular magnetism, with the goal of turning a single molecule into a magnet.

It's an unprecedented design feat.

"The idea is to actually magnetize a single molecule," says Preuss. "If we can make this work, it would be the first rational synthesis of a single-molecule magnet in the world."

Magnets have two poles and can point in either direction. That means they're able to encode one "bit" - that is, a unit of information having one of two values (which underlies all computer language).

The single-molecule magnets (SMMs) Preuss wants to create could become the smallest method of storing information yet.

Currently, data storage based on magnetism, such as the magnetic tape found inside audiocassettes, videocassettes and floppy disks, relies on the phenomenon of "bulk ferromagnetism" - the interactions between the hundreds or thousands of molecules - to maintain its magnetic properties.

But Preuss's proposed SMMs don't need to interact with molecules around them to stay magnetic. "This allows data density to be increased and enables us to store the same amount of data in a fraction of the space," she says.

A few SMMs have been created previously, mostly by serendipity. Not only were they unplanned, but they were also impractical. Their useful temperature range - at which they become and remain magnetized - is around -250 C.

Now, Preuss is working on a coherent synthesis of an SMM that can be created consistently from a chemical recipe and can retain its magnetism at a usable temperature.

"If we're successful, this would be a huge technological leap for the electronics industry," she says.

This work is sponsored by the Natural Sciences and Engineering Research Council.