Is carbon a magnetic material? Until very recently the answer to that question was a definite no. However, recent experiments have indicated that, in certain forms, carbon can show strong magnetic characteristics. Carbon is a vital element for life on Earth and shows remarkable versatility. The possibility that it can be coaxed into magnetic behaviour opens up a huge vista of potentially useful applications. In addition, it throws the conventional theory on strongly magnetic materials into some confusion. To date, the observation of ferromagnetic properties has only been observed as a small fraction of some carbon samples. Pure carbon can take many forms, ranging from graphite to diamond, alongside more recently discovered forms such as the fullerenes – C60. Ferromagnetic behaviour has so far been observed in pressure and light polymerised fullerenes and irradiated graphite, amongst others. These fullerenes form a series of one-, two- and three-dimensional phases. The ferromagnetic phase remains at room temperature, although magnetic domains were found to be diluted in a matrix of non-magnetic material.
The FERROCARBON project brings together an array of European scientific talent from Italy, Spain, Germany, Sweden, Russia and the United Kingdom – all world leaders in this field. Their skills cover the broad competencies in theoretical and experimental chemistry and physics, plus material science and engineering, which are needed to achieve the challenging task of understanding how to produce magnetic carbon routinely and in bulk. There are a number of competing experimental and theoretical approaches to the production and understanding of magnetic carbon which the FERROCARBON project will need to evaluate, analyse, improve and synthesise to achieve its aims. These aims are straightforward: to discover how to control the magnetic properties of carbon-based materials; to understand the microscopic origin of ferromagnetism in these materials; and to discover new, useful magnetic carbon materials.
A systematic characterisation study of proton-bombarded graphite, bulk fullerenes and carbon-based polymers and thin fullerene films will be undertaken, in parallel with theoretical work on the introduction of ‘defects' in these materials. The productionmethods for fullerene polymers will be refined to improve the quality and quantity of the magnetic phase so that it can be characterised more precisely. In parallel, theoretical calculations will be used to investigate a variety of carbon structures to predict the effects of structural and chemical defects. The results of both the experimental and theoretical work will be a rational basis for new magnetic material design based on carbon.
The work will also explore the characteristics of other fullerene phases that show exceptional strength and hardness, as well as a wide variety of electronic properties and other magnetic properties such as magnetostriction (a change in physical dimension due to a change in magnetic field). These properties herald application opportunities in sensors, optics and spintronics. The prospect of being able to control the properties at nano-scale to produce, in effect, molecule-sized magnets is particularly exciting. This could lead to significant advances in data storage and security/identification. The discovery of a bio-compatible ferromagnetic carbon also opens up possibilities for magnetic control of drug delivery, contrast agents for MRI scans, and new approaches to cancer therapy. FERROCARBON also aims to make a considerable input to fundamental science. The existence of carbon-based magnetic material requires a root-and-branch rework of magnetic theory. The existing theory for magnetism in elements with only ‘s' and ‘p' electron orbits (such as carbon) is in an embryonic state and will develop rapidly in the next few years. Members of the NEST project team will be leading this new science and expect to point the way towards a single-phase bulk carbon magnet.