Researchers have been able to create and annihilate magnetic properties in a non-magnetic material. This is a step toward improving the storage and retrieval of information on hard drives and other magnetic memory devices.

"The important thing is that it's reversible. Changing the voltage of the applied electric field demagnetize the material again," says Hendrik Ohldag, a co-author of a research paper describing the results.

Scientists move the electric tip along the surface and apply a positive voltage. The electric field aligns the spins of the electrons in the nonmagnetic material, and the ordering creates magnetic properties. If the voltage is reversed, the spins once again become disordered and magnetism is lost. "That means this technique could be used to design new types of memory storage devices with additional layers of information that can be turned on and off with an electric field rather than the magnetic fields used today," says Ohldag. "This would allow more targeted control, and would be less likely to cause unwanted effects in surrounding magnetic areas."

By designing a particular material, the scientists were able to achieve a multiferroic state where magnetism can be manipulated with an electric field. In the ferromagnetic materials used in hard drives, the magnetic properties are determined by the orientation of electron spins.

These spins can be manipulated by applying a magnetic field – flipping them from north to south, for instance, to store information as ones and zeroes. The research team started with an antiferromagnetic material – one that has small patches of magnetism that cancel each other out, so that overall it doesn't act like a magnet.

Both antiferromagnets and ferromagnets show magnetic properties only below a certain temperature, above which they become nonmagnetic. By doping an antiferromagnetic material with lanthanum, the researchers found they could tune the properties of the material in such a way that electricity and magnetism could influence each other at room temperature. They were able to affirm their results by using a scanning transmission x-ray microscope to detect magnetic spin.

The team would now like to test other materials to see if they could achieve an even more pronounced effect.