Graphene has very many strengths, but there is one thing it isn’t and that is magnetic. Now, a team of researchers has found that the insertion of a little lead into the planar graphene structure can change that.
The team — from from IMDEA Nanoscience, the Autonomous University of Madrid, the Madrid Institute of Materials Science (CSIC) and the University of the Basque Country — has shown that small islands of lead inserted beneath sheets of graphene make the structure highly magnetic. The work is published in Nature Physics and Science Daily explains how it works:
The secret is to intercalate atoms or Pb islands below the sea of hexagons of carbon that make up graphene. This produces an enormous interaction between two electron characteristics: their spin — a small ‘magnet’ linked to their rotation — and their orbit, the movement they follow around the nucleus.
To obtain this effect, the scientists laid a layer of lead on another of graphene, in turn grown over an iridium crystal. In this configuration the lead forms ‘islands’ below the graphene and the electrons of this two-dimensional material behave as if in the presence of a colossal 80-tesla magnetic field, which facilitates the selective control of the flow of spins.
That’s quite something. And it also has some very real and plausible applications. Magnetism lies at the heart of a lot of digital storage, and graphene could provide a bomb-proof material to make such devices from, or it could be used to create robust, nano-size magnetic sensors. Either way, making graphene magnetic is an interesting and exciting step in the super material’s life. [Nature Physics via Science Daily]