Extended magnetic systems
We first consider three-dimensional spin textures in extended magnetic systems, which act as effective playgrounds for the study of fundamental topological structures and their behaviour. In these larger magnetic microsystems, we observe structures that are analogous to our every day life – magnetic vortices (tornadoes), Bloch points (singularities, like a black hole!) and vortex rings (similar to bubble rings in water).
3D magnetic nanostructures
We also pattern magnetic materials in three-dimensions at the nanoscale. The three-dimensional architectures provide a new means of incorporating exotic magnetic properties, resulting in complex magnetic textures and dynamic behaviours. These new properties – as well as opportunities for higher densities – offer exciting possibilities for the next generation of technological devices.
Alternative types of ferroic order, such as antiferromagnets (AFMs), are of growing interest due to the promise for stray-field-free topological structures, ultra-fast switching, and recent developments in electrical control of their configuration. However, compared to ferromagnets, these systems are yet to benefit from the latest developments in X-ray science. We are working to develop the necessary experimental capabilities to visualise this order in three-dimensions.
In recent years we have been working to develop new experimental capabilities to study three-dimensional magnetic systems – both to visualise, and to fabricate, magnetic systems in 3D. Although most of our work focuses now on making use of these techniques to study the physics of 3D nanomagnetism, we continue to work to improve these techniques to enhance our understanding of the material systems.
Specifically, to visualise three-dimensional magnetic configurations, we use a technique similar to that of a CT scan in a hospital: magnetic tomography. We harness synchrotron X-rays to measure magnetic images at different directions and reconstruct the internal magnetic nanostructure with advanced algorithms. By combining this with pump-probe techniques, we can observe not only the static, but also the dynamic behaviour of the magnetisation textures – giving insight into how they evolve within a system.
In addition, to fabricate three-dimensional magnetic nanostructures, we make use of techniques reminiscent of 3D printing – but at the nanoscale. This allows us to design and tailor the three-dimensional shape of our structures, providing control over their properties and allowing for direct integration into microelectronics circuits.