3 dimensional magnetic data storage

Magnetic materials are used in a diverse range of applications in the modern day world but are well known for their importance within the data storage industry. Conventional storage within computers use a hard disk drive which consists of a platter upon which are magnetised regions, hundreds of nanometres across. Each tiny region acts as a bar magnet, with associated north and south pole. Digital information is stored by changing the direction in which the magnetic north points for each region. In order to increase the amount of information that can be stored on a hard disk drive the magnetic regions need to be reduced in size. This has been the general strategy for increasing areal density over the past 10 years. Unfortunately, when magnetic regions for a given material reaches a critical volume, the thermal energy becomes comparable to the energy maintaining a given magnetic state. This
is known as the super paramagnetic limit and is a fundamental limit in magnetic data storage. Numerous strategies are being investigated to reduce the effect of thermal fluctuations, such as the use of high anisotropy materials or patterned media.
However these methods will eventually hit the fundamental limit, since the overall disk is confined to a two-dimensional plane. New magnetic technologies are needed to maintain the steady increase in areal density over the next 50 years and the obvious way to achieve this is to store information in all three dimensions rather than confining the information to a single plane. Three-dimensional nanomagnetic structures have had limited study to date due to difficulties in fabrication. This studentship will involve the fabrication of novel three-dimensional magnetic structures using a cutting edge direct laser writing lithography technique. Structures of different
geometry, dimension and material will be made in order to investigate the effect of three-dimensional nanostructuring upon magnetic properties. The structures will be subject to a diverse range of characterisation techniques available at Cardiff
including atomic force microscopy, scanning electron microscopy and magnetooptical characterisation. It’s expected that the structures will also be subject to novel experiments at synchrotron facilities such as the Diamond Light Source. The project
may ultimately help pave the way to new three-dimensional magnetic storage devices.