The group's interests are broad, ranging from understanding the behaviour of the magnetic vortex lattice in high Tc superconductors through to understanding the next generation of magnetic storage media.

Our research into bulk high T_c superconductors is conducted using the Muon Spin Rotation (µSR) technique at the Paul Scherrer Institute (PSI) in Switzerland and the Rutherford Appleton Research Laboratory in the UK. The results from these experiments are complemented by Small Angle Neutron Scattering (SANS) measurements, also available at PSI, and the Institut Laue Langevin (ILL) in France. This work is also aided by SQUID magnetometry and other bulk measurements performed at St. Andrews.

Our studies of magnetic nanoparticle systems and recording media are undertaken using SANS and Polarised Neutron Reflectivity (PNR). By combining neutron scattering techniques with analytical modelling and micromagnetic simulations, we have been able to extract important information about the local magnetic behaviour of both longitudinal and perpendicular media, which may prove important for the understanding and future development of this technology.

The combined use of µSR and SANS provides a very powerful approach to the study of vortices in superconductors. Recent work in this area includes microscopic observation of vortex glass phases, transitions and vortex correlations in high-Tc materials.

As well as probing the bulk properties of superconductors, the µSR technique can also be adapted to investigate superconductivity and magnetism in thin film samples. A recently developed method, known as the Low Energy Muon (LEM) technique, moderates the momentum of the muons prior to entering the sample. Consequently, the implantation depth of the muons is sharply reduced and systems with reduced dimensions can be probed. The LEM technique is complemented well by PNR where the variation of the magnetisation along a direction normal to the surface of the film can be investigated. A recent example of the use of LEM is the observation of the coexistence of magnetism and superconductivity in thin films.

At St. Andrews, we have access to a number of measurement techniques including a 5T Squid magnetometer, ac-susceptibility, a transport rig and torque magnetometry. Sample preparation facilities are also available as well as access to a wide range of other shared facilities within the School of Physics and Astronomy and SUPA.