Egg shaped magnets hold promise for spinRAM memories
1 min read
Researchers at the US National Institute of Standards and Technology (NIST) have used electron beam lithography to make thousands of nickel-iron magnets, each about 200nm in diameter, as part of its research into nanoscale magnetic materials, devices and measurement methods for future magnetic data storage systems.
The researchers created three different egglike shapes and found that even small distortions in the magnet's shape can lead to significant changes in its properties. After probing the magnets with a laser and analysing what happens to the 'spins' of the electrons, the researchers discovered the more egg like the magnet, the more complex the wave patterns and their related frequencies.
According to the research team, the egg effects explain erratic behaviour observed in large arrays of nanomagnets, which can affect switching in magnetic devices. Shaping magnets like eggs breaks up a symmetric frequency pattern found in ellipse structures and offers an opportunity to customise and control the switching process.
The study may also be useful in developing spinRAMs: random access memories based on interactions between electron spins and magnetised surfaces.
"For example, intentional patterning of egg like distortions into spinRAM elements may facilitate more reliable switching," says NIST physicist Tom Silva.
