“Purely organic radicals are interesting in a whole lot of applications,” said Dr Benedetta Casu. “They can be used in storage elements, batteries, sensors and for biomedical applications. They could also be used in the construction of a quantum computer.”
Magnets made of organic materials have a number of advantages over the classic metal or alloy magnets. They are said to be chemically more flexible, cheaper to make, and can be better adapted to various purposes and varying designs. In practice, researchers want to apply both types of magnets in electronics – in spintronic elements.
The researchers investigated the interface between a single rutile crystal and an organic radical using a high resolution x-ray spectroscopy procedure combined with theoretical calculations. The researchers call this link between conventional and organic magnets the ‘spinterface’ because it combines the ideas of ‘spin’ and ‘interface’.
“In this experiment, organic radicals are held in place physically, and the magnetic momentum was maintained between the different materials,” Dr Casu explained. She says it worked well until there was a tiny defect on the relevant surface of the rutile crystal. “In that case, the organic radical bonded chemically with the reactive point of the defect, wiping out the magnetic momentum,” Dr Casu said.
“Knowing the problem, we can try to bypass it. For example, by depositing similar materials on native SiO2 surfaces that are flat and inert, the magnetic moment stays intact. You can passivate the surfaces with specific materials, as is done already in organic field effect transistors, or you can modify the magnet chemically in order to attach it to the surfaces by using another functional group, leaving the part that carries the magnetic moment intact.
“In the real word, we expect surfaces to have defects. At the moment, we are investigating one of our purely organic magnets on a copper surface in order to simulate real contacts.”
