INTERESTING ARTICLES: Researchers make graphene magnetic, clearing the way for faster everything

Researchers make graphene magnetic, clearing the way for faster everything

Ryan Whitwam

Graphene has many fantastic properties that could change the course of human civilization. It’s chemically stable, highly conductive, and incredibly strong. One thing it is not, however, is magnetic. This is one of the issues cited by the likes of IBM, which has tried to dampen expectations for a future of super-efficient microprocessors built on graphene. That might not be a problem much longer, though. Scientists from the University of California, Riverside have successfully created graphene that has magnetic properties.

To make this happen, the team started with a sheet of regular (but still awesome) non-magnetic graphene. The graphene was placed on a layer of magnetic yttrium iron garnet, which actually transferred its magnetic properties to the graphene without disrupting its structure or other properties. Most magnetic substances interfere with graphene’s ability to conduct electricity, but yttrium iron garnet is also an electric insulator. That meant it was unlikely to negatively affect the graphene’s electron transport properties.

When removed and exposed to a magnetic field, the team found their treated graphene’s Hall voltage depended on the magnetic linearity of the yttrium iron garnet. This told the scientists that their graphene was magnetic all on its own and that magnetism had come from exposure to the yttrium iron garnet layer. This property should last indefinitely as it is not the result of depositing material on the graphene, but comes from the graphene itself.

It has been possible in the past to create magnetized graphene, but this always relied on adding additional magnetic compounds or coatings to the raw graphene — often lead or iron. This rather defeats the purpose of graphene by adding additional complications. It’s already hard enough to produce large quantities of sufficiently pure graphene without adding these additional complications. The addition of extra atoms to graphene’s single atom structure also screws up its electrical properties in the same way exposure to non-insulating magnetic materials can. What’s different this time is that the graphene is still just pure graphene.

The potential applications for magnetic graphene could be anything from information processing to advanced medicine. Researchers see a big future for magnetic graphene in the burgeoning field of spintronics — that’s shorthand for “spin transport electronics.” Spintronics involves processing a signal using magnetic spin rather than electric charge.

Eventual consumer and business applications for spintronics technology could be faster processors and memory with vastly higher capacities. Silicon transistors have been shrinking in size with every new generation of processors from Intel, ARM, and other firms. We’re down to 14nm process technology these days, which is nearing fundamental atomic limits. Intel also has 10nm technology on its roadmap, and 5nm is expected to happen around 2020. This might be the functional end of Moore’s Law, though.

Magnetic graphene utilizing spintronics could be there to take over when traditional silicon transistors simply can’t get any smaller. A graphene transistor could work on the atomic scale, but we’ve still got a few years to get things figured out before magnetic graphene becomes a necessity.

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