UAB Scientists break the hard drive miniaturisation limit

Magnetic memory-based information storage systems are getting smaller and smaller, while their capacities are getting larger. However, there is a limit to how small they can get. If the tiny magnets used to store information are smaller than around five nanometres (millionths of a millimetre), vibrations caused by temperature can erase their orientation and, therefore, the information they contain. This is known as the superparamagnetic limit, which physically limits the capacity of magnetic storage systems to some 100 Gbit/in2.

An international team of scientists, which included ICREA researcher Josep Nogués of the UAB’s Physics Department, has discovered a way of breaking that limit. The researchers have discovered that it is possible to attain extra stability of the magnetic nanoparticles that store information if they are anchored to a matrix with particular magnetic properties (antiferromagnetic matrix). The discovery opens new horizons for magnetic storage technologies, the miniaturisation of such common items as computer hard drives and improvements of other magnetic systems.

The scientists made the discovery using a system made up of cobalt particles of between 3 and 4 nanometres. When these particles are distributed in a matrix similar to one normally used as a base for magnetic particles, their capacity to store information is lost when the temperature rises. However, the same particles are much more resistant to the effects of temperature if they are distributed in a matrix with antiferromagnetic properties.

The researchers have already contacted the Seagate Technology Company, which manufactures magnetic computer memories, to evaluate the application of this research to the miniaturisation of IT components