The idea is fascinating: when an information unit (in the binary world either a zero or a one) requires only a single atom or molecule, we would be able to store an unimaginable amount of data on a minimal surface area. And in theory this is even possible, because certain atoms can be magnetized such that their magnetization can only be in one of two directions: spin up or spin down. By combining a large number of such atoms or molecules, information can be stored.

Before this theory can be turned into a reliable practical application, quite a few hurdles have to be overcome. It is not so easy to find molecules that store the (magnetic) information not only for a short period, but can also store it permanently. And it is even more difficult to attach such molecules to a fixed surface in order to construct a storage medium.

An international research team under the leadership of chemists from the ETH Zürich have developed a method that could offer a solution to the latter problem. Professor Christophe Copéret and his team developed a molecule that contains a dysprosium atom at its center (dysprosium is one of the rare-earth metals). This atom is surrounded by a molecule 'frame' that serves as a transport vehicle.

The researchers also found a way to deposit these molecules on a surface of silicon oxide nano particles and at 400°C bake then in place. With this, the transport molecule falls apart so that the nano particles with 'free-standing' dysprosium atoms remain. These can be magnetized and keep their magnetization orientation.

This magnetizing currently only functions at temperatures near absolute zero (at –270 °C) and also last only about a minute and a half. There is therefore an intensive search for methods that also function at higher temperatures and the magnetization of which is stable for longer periods of time.