[LINK] magnetic vortex cores

stephen at melbpc.org.au stephen at melbpc.org.au
Fri Jan 16 01:17:40 AEDT 2009

Hi Fred and all,

> > Something interesting:  magnetic vortex cores  (nano-sized & 
> > everywhere) Recently seen in magnetism and still only 60,000
> > science hits in google. And of those google hits most of the
> > 'basic' research is still commercial and use these new facts
> > about our universe. But soonish, deeper science will catchup
> > and imho magnetic vortex cores might 'revolutionize' science
> Fascinating stuff! Can you provide, or point us to, a layperson's
> description of what they are and their implications? Ta,  Fred 

Yes Fred they are fascinating,  magnetic swirls within and without.

Magnetic vortex cores, discovered in 2002, are everywhere around us.

They are important, yet, only thus far being developed for their 2D
flat-surface and darn near indestructible nano-memory abilities and
the 3D nature of these 'magnetic-swirls-of-the-universe' overlooked.

For example, here is an only media-like :) news article i've found,
certainly not, as we both seek, an answer to what vortex cores are. 


"Physicists at Rice Decode 3D Structure of Tornado-Like Magnetic Vortex"..

Rau and postdoctoral researcher Jian Li used a one-of-a-kind scanning ion 
microscope to first create and then measure ultra-thin circular disks of 
soft magnetic cobalt. Their goal was to trap and image a single magnetic 
vortex .. a cone-like structure .. if the vortex spins in a right-handed 
direction, the cone points up, and if the vortex spins left, the cone 
points down.

The single vortex (in cobalt) was found measuring six microns in diameter.

"Most people are familiar with the vortex: we see it in satellite photos 
of hurricanes, in whirlpools and in bathtub drains - even in Van Gogh's 
famous painting 'Starry Night,'" Rau said. 

"In nanomagnetism however, vortices are quite hard to see experimentally. 

Most often, we must infer their existence from some other measurement.

"Our high-resolution spin microscope is the exception here," he said. 

"It allows us to map not just the overall vortex, but also the detailed 
location and orientation of millions of magnetic moments that combine 
physical forces which create the overall structure."

The instrument Rau and Li used in the study is a scanning ion microscope 
with polarization analysis, or SIMPA. The device consists of a highly-
focused ion beam that fires gallium ions at surfaces of flat cobalt 
samples.. Then using a different setting, the gallium ions are fired at 
the cobalt surface in such a way as to induce the release of electrons. 

The electrons, which carry specific information about the magnetic state 
of the cobalt atoms that release them, are captured by a detector and 

Rau said better understanding of magnetic vortices could allow 
breakthroughs in the design of nanostructures for ultra-high-density hard 
disk media, non-volatile magnetic random access memory and novel magnetic 
logic gates that could replace volatile semiconductor logic. Compared to 
regular electronic devices, the magnetic devices would be faster, 
smaller, use less power, create less heat and they wouldn't lose 
information when power was turned off.

Cheers Fred,
Stephen Loosley
Victoria, Australia

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