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Journalism of Courage
Scientists have discovered a new combination of materials that paves the way for faster and more effective storage in electronic devices such as computers and smartphones.
Researchers at Uppsala University in Sweden discovered that the so-called magnetic damping can be made extremely small, eliminating energy losses in the dynamics of magnetic materials.
The material identified is a binary metallic ferromagnetic alloy of cobalt and iron with damping approaching the magnitude of 10-4. Damping this low has previously only been observed for metalloids or magnetic insulators, such as certain iron oxides, researchers said.
Magnetic materials have proven to be very effective for the storage and transfer of data and were the natural successors to the punch card that was first used in the early 1700s, they said.
Subsequent developments, including magnetic tape and hard discs, enabled an explosion in information technology and today about 70 per cent of all data is stored in magnetic media.
Thus far, researchers have created micrometre-sized magnetic storage devices and achieved transfer speeds in the order of nanoseconds to meet today’s storage needs, with data transfer in the magnitude of 100 petabytes a day. “To continue to meet advanced storage needs, we need smaller and faster devices and this requires either a new
technology for storage and/or the discovery of new magnetic materials,” researchers said.
They have discovered just such a new magnetic material in the iron-cobalt alloy, and found that damping can be used to achieve maximum energy-efficient data transfer inside the material.
The damping in a magnetic material can be compared with the friction in a hockey puck, which glides along the ice, and which stops after a while due to resistance against the surface.
The damping parameter in magnetic materials can be likened here to the coefficient of friction between the hockey puck and the ice. The phenomenon of low damping in iron-cobalt can be explained by a unique property in the internal electronic structure, in which the damping is proportional to the number of electronic states at the highest occupied energy level.
This new discovery on low damping in the iron-cobalt alloy, along with the fact that the material is easy to produce, is magnetic even at room temperature, and that both iron and cobalt are common elements, can lead to this material becoming a standardised reference material for comparison in the hunt for new and even better alloys. The study was published in the journal Nature Physics.
