Washington DC (SPX) Apr 29, 2011
Magnetics researchers at the National Institute of Standards and Technology (NIST) colored lots of eggs recently. Bunnies and children might find the eggs a bit small-in fact, too small to see without a microscope.
But these "eggcentric" nanomagnets have another practical use, suggesting strategies for making future low-power computer memories.
For a study described in a new paper,* NIST researchers used electron-beam lithography to make thousands of nickel-iron magnets, each about 200 nanometers (billionths of a meter) in diameter.
Each magnet is ordinarily shaped like an ellipse, a slightly flattened circle. Researchers also made some magnets in three different egglike shapes with an increasingly pointy end. It's all part of NIST research on nanoscale magnetic materials, devices and measurement methods to support development of future magnetic data storage systems.
It turns out that even small distortions in magnet shape can lead to significant changes in magnetic properties. Researchers discovered this by probing the magnets with a laser and analyzing what happens to the "spins" of the electrons, a quantum property that's responsible for magnetic orientation. Changes in the spin orientation can propagate through the magnet like waves at different frequencies.
The more egg-like the magnet, the more complex the wave patterns and their related frequencies. (Something similar happens when you toss a pebble in an asymmetrically shaped pond.) The shifts are most pronounced at the ends of the magnets.
To confirm localized magnetic effects and "color" the eggs, scientists made simulations of various magnets using NIST's object-oriented micromagnetic framework (OOMMF).** (See graphic.) Lighter colors indicate stronger frequency signals.
The egg effects explain erratic behavior observed in large arrays of nanomagnets, which may be imperfectly shaped by the lithography process. Such distortions can affect switching in magnetic devices.
The egg study results may be useful in developing random-access memories (RAM) based on interactions between electron spins and magnetized surfaces. Spin-RAM is one approach to making future memories that could provide high-speed access to data while reducing processor power needs by storing data permanently in ever-smaller devices.
Shaping magnets like eggs breaks up a symmetric frequency pattern found in ellipse structures and thus offers an opportunity to customize and control the switching process.
"For example, intentional patterning of egg-like distortions into spinRAM memory elements may facilitate more reliable switching," says NIST physicist Tom Silva, an author of the new paper.
"Also, this study has provided the Easter Bunny with an entirely new market for product development."
H.T. Nembach, J.M. Shaw, T.J. Silva, W.L. Johnson, S.A. Kim, R.D. McMichael and P. Kabos. Effects of shape distortions and imperfections on mode frequencies and collective linewidths in nanomagnets. Physical Review B 83, 094427, March 28, 2011.
Share This Article With Planet Earth
National Institute of Standards and Technology (NIST)
Space Technology News - Applications and Research
Researchers working to advance predictability research initiatives
Norman OK (SPX) Apr 27, 2011
Faculty from the University of Oklahoma School of Meteorology are leading the school's predictability research initiatives with multiple projects that could one day lead to more accurate forecasts of weather-related events, including landslides and tornadoes. In the Southern Plains region of the United States, people think of thunderstorms and tornadoes when severe weather is forecasted. H ... read more
Thousands queue for iPad 2 across Asia|
New polymer structures for use as plastic electronics
NIST nanomagnets offer food for thought about computer memories
Chinese pay price for world's rare earths addiction
Lockheed Martin Demonstrates Integration of MONAX Communications System with Air Force Base Network
Preparations Underway As US Army Gears Up For Large-Scale Network Evaluations
Global Military Communications Market In 2010
Raytheon BBN Technologies To Protect Internet Comms For Military Abroad
GSAT-8 put through its paces
Ariane Ariane 5 enjoys second successful launch for 2011
Ariane rocket launches two telecoms satellites
SpaceX aims to put man on Mars in 10-20 years
GPS Operational Control Segment Enters Service With USAF
Apple denies tracking iPhones, to fix 'bugs'
GPS IIF Satellite Delivered to Cape Canaveral
S. Korea probes Apple about tracking feature
Brazil's key airports set to go private
Extreme testing for rotor blades
ANA returns to profit, faces uncertain outlook
DLR measures the shape of a barn owl wing in flight
China's Huawei sues ZTE for patent infringement
Zeroing in on the Elusive Green LED
Conducting ferroelectrics may be key to new electronic memory
LED efficiency puzzle solved
NASA Mission Seeks to Uncover a Rainfall Mystery
Satellite tracking of sea turtles reveals potential threat posed by manmade chemicals
GOES-13 Satellite Eyeing System With High Risk of Severe Weather
Running ring around hurricanes predictions
Mercury converted to its most toxic form in ocean waters
Researchers Find Fat Turns Into Soap In Sewers
Toxic chemicals found in pet dogs
Toxic mud disaster leaves deep scars in Hungary
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement|