Investigating Vortex Behaviour in Superconducting Thin Films through Magnetic Microscopy Techniques

Magnetic microscopy is the process of creating accurate images of magnetic flux, to map its variations over a small region. In this thesis, magnetic microscopy was used to investigate the distribution and behaviour of magnetic flux (in the form of vortices) in superconductors. Two different magnetic microscopy techniques were used: Magneto-Optical Imaging and Scanning SQUID Microscopy. From each image of magnetic flux, the local distribution of supercurrent was also calculated using an inversion of the Biot-Savart law. This work centres on several separate yet related experimental investigations into the static and dynamic properties of magnetic vortices and supercurrents in thin film YBa2Cu3O7-δ superconductors.