Graphene, a sheet one atom thick made up of carbon atoms, has a huge number of qualities but lacks magnetic properties. Yet the hydrogen atom has the smallest magnetic moment. The magnetic moment is the magnitude that determines how much and in what direction a magnet will exert force.
"In other words, we can all remember having held a magnet in our hands and seeing how it was capable of attracting or repelling another magnet at a certain distance, which was greater or smaller depending on its power. Well, what really determined this behaviour was the magnetic moment of our set of magnets. The distance at which we began to feel the appearance of a force was specified by the spatial extension of their magnetic moments, and the fact that the force should attract or repel depended on the relative orientation between them; that is why when one of the magnets was turned round, they then attracted or repelled each other or vice versa," explained Miguel Moreno Ugeda, a nanoGUNE researcher.
"Our work reveals how when a hydrogen atom touches a graphene layer it transfers its magnetic moment to it," said Moreno. "In contraposition to more common magnetic materials such as iron, nickel or cobalt, in which the magnetic moment generated by each atom is located within a few tenths of a nanometre, the magnetic moment induced in the graphene by each atom of hydrogen extends several nanometres, and likewise displays a modulation on an atomic scale," he added.
The experiments were carried out with the help of a tunnel-effect microscope. This microscope allows matter to be imaged and manipulated on an atomic scale. Likewise, the results show that these induced magnetic moments interact strongly with each other at great distances (compared with the atomic scale) while also abiding by a particular rule:
the magnetic moments are added or neutralised depending critically on the relative position between the absorbed hydrogen atoms. What is more, and of equal importance, is that "we have managed to manipulate the individual hydrogen atoms in a controlled way, and this has enabled us to freely establish the magnetic properties of selected regions of graphene," stressed Moreno.
In the quest for magnetism
Ever since 2004 when it was first possible to obtain graphene, laboratories across the world have been trying to add magnetism to the long list of properties of this purely two-dimensional material. This interest arises mainly out of the fact that graphene is, a priori, an ideal material for use in spintronic technology.
This promising technology is aiming to replace traditional electronics by transmitting both magnetic and electronic information at the same time, which could give rise to a new generation of more powerful computers.
So "the results obtained in this work, which indicate the possibility of freely generating magnetic moments in the graphene and showing how these moments can communicate with each other over great distances, are paving the way for a promising future for this material in the emerging field of spintronics," concluded Moreno.
Irati Kortabitarte | EurekAlert!
Why geckos can stick to walls
19.11.2018 | Jacobs University Bremen gGmbH
Get rid of sweat at the push of a button
19.11.2018 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
19.11.2018 | Science Education
19.11.2018 | Ecology, The Environment and Conservation
19.11.2018 | Life Sciences