New Means for Affecting Magnetism Discovered
Everybody is familiar with magnets and there is a good chance many of us are also familiar with what happens when a magnet breaks; you get two magnets. The reason breaking a magnet gives you two is that the magnet itself is made up of many smaller magnets, but when you get down to the size of atoms, magnetism is not as well understood. Researchers at the London Center for Nanotechnology have recently made a discovery about the directionality of magnetic atoms that could have many impacts.
For the magnets we deal with on a daily basis, the directionality or anisotropy or the magnet is determined by its shape. As atoms are incredibly small, it is hard to characterize a shape for them, which makes it hard to manipulate their magnetic anisotropy. At least that is what had been believed, but the LCN researchers have discovered the Kondo effect can also impact this property. The Kondo effect comes from a magnetic atom and metal coupling, and the researchers discovered the relationship measuring the anisotropy with a scanning tunneling microscope of cobalt atoms between a copper surface and atomically thin sheet of copper nitride.
Being able to affect the magnetic anisotropy of an atom could be very powerful, especially as the Kondo effect can be controlled and tuned electrically. This could lead to new kinds of magnets that rival the strength of rare earth magnets, without the rare and expensive metals.
Source: London Center for Nanotechnology