Graphene is incredibly strong, lightweight, and conductive. However, it is not magnetic. This disadvantage limits its usefulness in spintronics. New research addresses this problem.
Spintronics is a growing field that scientists say will eventually rewrite the rules of electronics. This will lead to more powerful semiconductors, computers and other devices. In such a promising area, such a versatile material as graphene would be useful.
In a study published today in the journal Physical Review Letters, the researchers describe how they coupled a magnet with graphene and created what they describe as an “artificial magnetic texture” in a non-magnetic material.
“Independently of each other, graphene and spintronics have incredible potential to fundamentally change many aspects of business and society. But if you can combine them together, the synergistic effects will surprise the world, ”said lead study author, Ph.D. Nargess Arabchigavkani, who conducted the study.
Also, the international goppa of scientists led by the University of Buffalo includes specialists from the King Mongkut Ladkrabang Institute of Technology in Thailand, Chiba Universities in Japan, science and technology in China, Nebraska in Omaha, Nebraska Lincoln and Uppsala in Sweden.
For their experiments, the researchers placed a 20 nm (nanometer) thick magnet in direct contact with a graphene sheet. It was a layer of carbon atoms arranged in a two-dimensional honeycomb lattice less than 1 nm thick.
“To get a feel for the difference in size, compare laying bricks to a sheet of paper,” explains senior study author Jonathan Bird.
The researchers then placed eight electrodes at different points around the graphene and magnet to measure their conductivity.
The electrodes surprised scientists – the magnets caused an artificial magnetic texture in graphene. It persisted even in areas of graphene far from the magnet. Simply put, the close contact between two objects caused the normally non-magnetic carbon to behave differently. It has shown properties similar to those of common magnetic materials – iron or cobalt.
The results obtained raise important questions concerning the microscopic origin of the magnetic texture in graphene.
Most important, the scientists say, is the extent to which induced magnetic behavior arises from the effects of spin polarization and / or spin-orbit coupling. They are known to be closely related to the magnetic properties of materials and to the emerging spintronic technology.
Rather than using the electrical charge carried by electrons (as in traditional electronics), spintronic devices seek to exploit a unique quantum property of electrons known as spin (which is analogous to the Earth’s rotation around its own axis). Spin makes it possible to pack more data into smaller devices. This increases the power of semiconductors, quantum computers, storage devices, and other digital electronics.