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Friday, April 15, 2011

#MATERIALS: "Magnetic graphene harnesses Kondo effect"

Pure sheets of carbon—graphene—can be made magnetic by introducing patterns of vacancies into their crystalline lattice, according to researchers at the University of Maryland. By controlling the magnetic properties of graphene semiconductors with vacancy-doping, the researchers hope to enable the pure carbon material to tackle new applications as magnetic sensors and random access memories (MRAMs).


Artist's rendering of a graphene transistor showing gold electrodes (yellow), silicon dioxide (clear), silicon substrate (black) and graphene (red), with inset showing graphene lattice vacancy defects (blue). Source: University of Maryland.

Semiconductors are usually made magnetic by doping with a metallic material such as iron or cobalt, but the University of Maryland team, led by professor Michael Fuhrer, claim that just introducing empty spaces into graphene's otherwise perfect hexagonal pattern—called vacancies—can dope the material for magnetism. Others have used surface treatments to make graphene magnetic, but the new method is said to work better by virtue of eliminating the need for any other material except carbon.

Further Reading: http://bit.ly/NextGenLog-gkEi