Posted on 03/10/2015 11:57:26 PM PDT by 2ndDivisionVet
Graphene, a material formed of a mesh of hexagonal carbon atoms, has, according to ExtremeTech author Ryan Whitwam, “many fantastic properties that could change the course of human civilization. It’s chemically stable, highly conductive, and incredibly strong.” In a recent New Yorker article, John Colapinto stated graphene “may be the most remarkable substance ever discovered.” One thing graphene is not, however, is magnetic.
Researchers at the University of California, Riverside have developed a way to induce magnetism in graphene while preserving its electronic properties. The research team did this by bringing a single sheet of graphene into close proximity to a magentic insulator.
Though graphene is intrinsically nonmagnetic, “it is possible,” says IEEE Spectrum Contributing Editor Dexter Johnson, “to induce magnetism in graphene by doping the material with magnetic impurities. Unfortunately, that process comes at the high cost of eliminating all the attractive electrical properties of graphene, such as its high conductivity.”
“This is the first time that graphene has been made magnetic this way,” says Jinh Shi, a professor of physics and astronomy at UC Riverside. Shi’s lab led the research. “The magnetic graphene acquires new electronic properties so that new quantum phenomena can arise. These properties can lead to new electronic devices that are more robust and multifunctional.”
First placing the single-layer graphene sheet on an insulating ferromagnetic thin film made of yttrium iron garnet (YIG) -- grown using laser molecular beam epitaxy in the UC Riverside lab -- magnetized the graphene while preserving its electronic properties. According to the researchers, graphene “simply borrows the magnetic properties from YIG.” Because the YIG is an electric insulator it did not disrupt the graphene’s electrical transport properties.
The research team subsequently carried out Hall-effect measurements, which indicated that the induced ferromagnetic graphene state arises from spin polarization of its electrons due to coupling between electrons in the two materials. Shi and his team also observed that the coupling enhances graphene’s normally low spin-orbit coupling, which could “lead to transport phenomena such as the quantized AHE [anomalous Hall effect], which are potentially useful for spintronics.”
The results of the study, conducted by Shi, Zhiyong Wang, Chi Tang, Raymond Sachs, and Yafis Barlas, were published online in January in Physical Review Letters.
I seem to recall a lab in china reporting this result last year.
Great post! Most informative.
Keep up the good work 2DV... Freepers everywhere love the cool items you post daily :-)
Hamiltonian or GTFO.
Petabytes of storage and multiple coupled Blue Gene processors in your AppleWatch....
bfl
I think they mean a mesh of hexagonal carbon rings, which are hexagonal because they contain 6 carbon atoms. A carbon atom is actually tetrahedral due to the positioning of the outer orbitals.
I am not certain how the magnetism was achieved. The article indicates that the magnetism was induced by placing the graphene in close proximity with the yttrium iron garnet sheet, allowing the electrons in the two materials to couple, suggesting that the two materials must be kept in close proximity in order to maintain the magnetism within the graphene. If so, then, technically, the graphene is still not magnetic. The article did not say that the graphene maintains the magnetic state when removed from the YIG. If it is the case that the graphene is only magnetic when close to the YIG, then the graphene did not become a magnet--it is only a transmitter of magnetism. That is still noteworthy, but it is not as big as claiming that the graphene actually became magnetic.
Change human civilization? How does this enable human levitation or teleportation or stop aging? Where’s my flying car dangit?
Carbon you say? How sacrilegous to the G-ds of Global Warming..Expect an attack on this climate denier!
Ha....might be able to magnetize Obama's moral compass.
Haven’t you heard? We must stop our addiction to carbon.
Can someone explain to a layman why magnetism is a big deal here? I am assuming it’s computer related. I am usually not so dense about this stuff.
Sounds like an 80's night club.
I’ll make an attempt.
Transistors.
Need to stop and start electron flow.
Because that is how information is encoded.
But electron flow in pure graphene can’t be stopped. So it’s useless in computers for transmitting and processing information.
Dope it with other substances and the superconductor quality of graphene goes bye-bye.
Magnetism does the job without doping, without interfering with graphene’s superconductivity.
Graphene takes Moore’s law to the limit in both space and time. But only if it can be controlled.
They’re saying in this piece that ‘borrowing’ magnetic properties from non-interfering material wrappings does the job.
How’s that?
Nice post 2nd Div!!!
That’s great. Thanks.
Keep the storage, make the watch smaller.
Things have to be of a certain size to accommodate human beings ... :-) ...
Exactly. No wait.. What? :)
It’s like Apple said with the new MacBook that they announced at their Apple Event. They said that it was the keyboard that defined the size of the MacBook. There are certain requirements for “human beings” ... :-) ...
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