Exploration of magnetic exchange springs promises new chapter in data storage

International research drawing upon expertise at the University of Southampton is set to influence a step change in data storage techniques by reducing the switching speeds of magnetic exchange springs to a trillionth of a second.

Scientists from the Universities of Southampton, Exeter and Oxford are working alongside project partners Seagate Technology and Diamond Light Source in the ‘Pico Second dynamics of Magnetic Exchange Springs’ programme. The three-year scheme seeks to advance the development of magnetic hard disks by creating faster writing and access to data.

The research project will channel over £640,000 of funding from the Engineering and Physical Sciences Research Council (EPSRC) as it accelerates the switching times of the storage devices from the nanosecond range of a thousand-millionth of a second through to a picosecond – a unit of time worth a trillionth of a second.

Co-Investigator Professor Graham Bowden, from Southampton’s Department of Physics and Astronomy, explains: “Over the past decade heroic efforts have been made to reduce the size of the individual magnetic bit, and speed up switching times. One of the main aims of this project is to move switching speeds into the pico-second regime. This can be achieved by pre-heating the magnetic bit using a laser pulse prior to applying a switching field. This process is known as Heat Assisted Magnetic Recording (HAMR). The physics underlying HAMR is challenging but we hope to detail the dynamics of magnetic exchange springs and feed new information into the field of nano-magnetism.”

The EPSRC researchers also plan to carry out x-ray detected ferromagnetic resonance (X-FMR) experiments at the Advanced Light Source facility in Berkeley, California, and Diamond Light Source in Oxfordshire. Such experiments will yield information on the dynamics of magnetic exchange springs.

Scientists in the project will need to overcome and explore difficulties posed through the HAMR technique, where heat from the laser beam diffuses through the magnetic-bit, reducing the strength of the magnetic moments, magnetic anisotropy and magnetic exchange, all on a short-time scale. Modelling this behaviour will be very challenging.

Postdoctoral researchers Drs Maciej Dabrowski and Andreas Frisk are now in place at Exeter and Diamond Light Source to progress work that also includes Professors Robert Hicken and Gino Hrkac from the University of Exeter, Professor Gerrit van der Laan at Diamond Light Source and Professor Thorsten Hesjedal at the University of Oxford.

Over the past decade, the Superconductivity and Magnetism Group at the University of Southampton, under the guidance of the late Professor Peter de Groot, has been a key player in research on magnetic exchange spring systems.

Find out more about Physics and Astronomy research at Southampton.