Researchers highlight potential of ‘magnetic’ graphene for spintronics

26 Feb 2021

Electrodes around a 20-nanometre-thick magnet. Image: University at Buffalo

A team of researchers has found a way to induce ‘artificial magnetic texture’ in graphene, which could lead to new tech developments.

Graphene is known as a ‘wonder material’ for a number of reasons. Comprising a one-atom-thick layer of carbon atoms, it is 200 times stronger than steel but is flexible and lighter than paper.

Earlier this month, MIT researchers built upon previous research they had carried out to show that adding an extra twist to the material can enhance its superconductivity. Graphene has also been used to develop biosensor prototypes, batteries for electric vehicles and greenhouse gas capture technology.

Graphene has many useful properties, however it is not magnetic. And this has stunted its potential in the area of spintronics, according to a team led by researchers from the University at Buffalo.

Spintronics

Spintronics is an emerging field that seeks to transform electronics and pave the way for more powerful semiconductors, computers and other devices. While traditional electronics relies on the electrical charge electrons carry, spintronics exploits their quantum properties, which offers potential for packing more data into smaller devices.

In new research, published in the journal Physical Review Letters, scientists said that pairing graphene with a magnet can induce what they describe as “artificial magnetic texture” in the non-magnetic wonder material. This could help lead to powerful spintronic devices.

“Independent of each other, graphene and spintronics each possess incredible potential to fundamentally change many aspects of business and society,” said Nargess Arabchigavkani, the paper’s lead author. “But if you can blend the two together, the synergistic effects are likely to be something this world hasn’t yet seen.”

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The research team includes scientists from University at Buffalo, King Mongkut’s Institute of Technology Ladkrabang in Thailand, Chiba University in Japan, University of Science and Technology of China, University of Nebraska Omaha, University of Nebraska-Lincoln and Uppsala University in Sweden.

Exploring the potential for magnetic graphene

These researchers placed a 20-nanometre-thick magnet in direct contact with a sheet of graphene, which is less than one nanometre thick.

“To give you a sense of the size difference, it’s a bit like putting a brick on a sheet of paper,” senior author Dr Jonathan Bird, who is a professor and the chair of electrical engineering at the University of Buffalo.

The researchers then placed eight electrodes on different parts of the graphene and magnet, allowing them to measure the conductivity of the materials. They found that the magnet had induced an artificial magnetic texture in the graphene, which even spread to parts of the graphene that weren’t in contact with the magnet.

The contact between the two objects caused the normally non-magnetic carbon to behave differently, exhibiting magnetic properties similar to common magnetic materials like iron or cobalt, researchers said.

They added that these findings raise important questions around the origins of the magnetic texture in the graphene, as well the extent to which spin polarisation and spin-orbit coupling – phenomena closely linked with magnetic properties of materials and emerging spintronics technology – induce the magnetic behaviour.

Lisa Ardill was careers editor at Silicon Republic until June 2021

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