Graphene shows record-breaking magnetic properties at room temperature

Graphene can change its electrical resistance in response to a magnetic field quicker than other materials, such as graphite or bismuth, which could one day change how we store data

By Jacklin Kwan

12 April 2023

Graphene is a two-dimensional material that is extracted from graphite, with atoms connected in a hexagonal lattice

Shutterstock/OliveTree

Almost 20 years after graphene’s discovery, research suggests it is the most magnetoresistant material we know of. This describes its ability to increase or decrease its electrical resistance in response to a magnetic field, which could one day have applications for how we store data.

Arranged as a sheet of carbon atoms in a honeycomb-like structure, graphene – a two-dimensional material extracted from graphite – was already known to be stronger than diamond and able to conduct electricity better than copper.

Now, Andre Geim at the University of Manchester, UK, and his colleagues have discovered that it also has unprecedented magnetoresistance at room temperature.

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To uncover this, the team first applied an electric field to some graphene to equalise the number of its charge carriers, which are responsible for creating a material’s electric current. These carriers are made up of electrons, which have a negative charge, and holes, which have a positive charge.

Pristine graphene, which has no flaws to its honeycomb structure, has equal numbers of electrons and holes. Since it is difficult to produce such graphene, the researchers used an electric field to adjust the structure of flawed graphene, enabling them to research the material in a more pristine state.

Flaws in the material’s structure affect its magnetoresistance, says Geim, who won the 2010 Nobel prize in physics for his research into graphene.