May 17, 2005

GW Discovery Extends Law of Physics

Two GW faculty members — Edward Della Torre, director of GW’s Institute for Magnetic Research and professor of engineering and applied science, and Lawrence H. Bennett, research professor of engineering and applied science — reported a newly observed phenomenon that extends a fundamental law of physics to magnetic nanostructures, extremely small magnetic particles about one-billionth of a meter in size, in the April 15 edition of Physical Review Letters.

These findings have practical applications for manufacturers of products using magnets, such as computer hard drives, as well as broader implications for the fields of physics, chemistry, and engineering.

Della Torre and Bennett discovered that when plotting magnetization as a function of decreasing temperature the curve was no longer evenly sloped as predicted by the Bloch T 3/2 law. Rather it showed a subtle upturn of the magnetization curve in the 10-50 K temperature range. They explain these visible anomalies in the law using the Bose-Einstein condensation theory, first predicted by Satyendra Nath Bose and Albert Einstein in 1924.

“One practical application of our discoveries would be to use this information to improve the way the life cycle of computer hard drives is modeled,” said Della Torre. “The magnets in hard drives affect whether the information on a hard drive will be stored for 10 minutes, 10 days, or 10 years, so it is important to both manufacturers and consumers to have a model that rapidly and accurately predicts how long a hard drive will last.”

The article, “Extension of the Bloch T 3/2 Law to Magnetic Nanostructures: Bose-Einstein Condensation” appears in Physical Review Letters, a prestigious physics journal published by The American Physical Society. It is the collaborative work of the pair, along with R.E. Watson of the Brookhaven National Laboratory, Department of Physics in Upton, NY.

Send feedback to: bygeorge@gwu.edu