January 24, 2013
100-Year-Old Mystery Of Talking Magnets Finally Solved
Watch the video "Torsional Magnetic Science"
April Flowers for redOrbit.com - Your Universe Online
The team, led by U of A professor and National Institute for Nanotechnology (NINT) researcher Mark Freeman, made the breakthrough with a new kind of high-resolution microscopy of magnetic materials, making it possible to finally harness a phenomenon known as the Barkhausen effect.
“I call this new tool a ℠scanning vortex probe microscope´ after the special magnetization pattern we used to make this discovery,” explained U of A graduate student Jacob Burgess, author of the theory and the model that revealed Barkhausen´s elusive secret.
Heinrich Barkhausen, for whom the Barkhausen effect is named, conducted a seminal experiment in 1919 that provided the first evidence of magnetic domains, which are the quilt-like patterns in the orientation of "magnetization" within magnetic materials. Barkhausen made his groundbreaking discovery by listening in on magnetic activity by wrapping a magnet with an electrical coil connected to a speaker. The messages Barkhausen received, however, were intermittent, idiosyncratic and impossible to translate. That is, impossible to translate until now.
“Barkhausen´s findings were very important for advancing our understanding of magnetism and for eventually using magnetic materials in applications like data storage,” says Freeman. “But the intricate details have proven surprisingly difficult to measure. In fact, the vague picture we´ve been working from has come to more perfectly represent what we don´t know.”
This discovery is a game changer, the study suggests, because magnetic thin films are critical in modern computing for storing information in every hard disk on every computer. This discovery provides potentially critical information for magnetic computation technology that may eventually be designed to replace hard drives. This would make it possible to engineer data storage that is so secure that it would be able to preserve data even if the computer crashed.
The findings of their study were recently published in the journal Science.