Magnetism as a physical characteristic is normally linked with metals such as cobalt, nickel, and iron. An organic mineral called graphite encompassing stacks of individual carbon sheets has indicated weak signs of magnetism and has baffled researchers.
A team of researchers including the Nobel prize-winning scientist Professor Sir Andre Geim, from the University of Manchester elucidated their findings in the journal EPL (Europhysics Letters).
Directed by Dr Irina Grigorieva, a research group demonstrated that magnetism in graphite crystals that are commercially available is found in micron-sized clusters of iron. Graphite magnetic formulation is the initial step in its adaptation as a bio-compatible magnet to function as effective biosensors in medicine and biology.
The research process included cutting a fragment of commercially available graphite into four segments, wherein the magnetization of each segment was calculated. Each segment showed drastic variations. Through this, the researchers confirmed that external factors including small impurities of other materials has a significant effect on magnetic response.
Scanning electron microscope (SEM) was employed to determine the presence of unusually heavy particles such as iron and titanium located beneath the surface, and was also confirmed with X-ray microanalysis. Due to the existence of oxygen, the magnetic particles can be either magnetite or titanomagnetite.
Further analysis was carried out concerning the number of particles required and the location of particles to galvanize the observed magnetism. The annotations following their experiments complied with the findings. It was concluded that the visualised magnetic particles are responsible for the overall magnetic signal in the sample.
Source: http://www.iop.org/