Magnetic flux decoration of type-II superconductors

Recent experimental studies of the flux line lattices in type-II superconductors are reviewed. All the experiments were performed using the Bitter decoration technique which provides means of direct observation of static vortex structures at the surface of the superconductor. Various aspects of vortex behaviour that can be studied in decoration experiments are considered, in particular vortex lattice ordering and the effects of pinning and anisotropy on the equilibrium vortex arrangement. New vortex phases, such as vortex chains and oval vortices, which were recently discovered in high-temperature superconductors, are also discussed.