Researchers develop magnetic memory with one bit per molecule

The team claims that by using an electric pulse, the metal organic molecule can be switched reliably between a conductive, magnetic state and a low conductive, non magnetic state. "The superparamagnetic effect prevents smaller bit sizes from being reached in a hard disk," explained Toshio Miyamachi, researcher at the Centre for Functional Nanostructures of Karlsruhe Institute of Technology (KIT). "We chose another approach and placed a single magnetic iron atom in the centre of an organic molecule consisting of 51 atoms. The organic shell protects the information stored in the central atom." This type of memory based on 'spin crossover molecules' apparently has the advantage of the writing process being purely electric. "Using a scanning tunnelling microscope, we applied defined electricity pulses to the nanometre sized molecule," added Wulf Wulfhe-kel, head of the research group at KIT's Physikalisches Institut. "This reproducibly changes not only the magnetic state of the iron, but also the electric properties of the molecule." The two magnetic configurations lead to varying levels of conductance, meaning the magnetic state of the molecule can be determined with a simple resistance measurement. The researchers say the study shows the feasibility and advantages of memories consisting of spin crossover molecules. They believe that the combination of these memristive and spontronic properties in a single molecule could open up an entirely new field of research.