Magnetic structures of high Tc superconductors: technique for decoration and data analysis

A description of the experimental set up for the decoration of vortex lattices is presented together with an analysis of the decoration parameters. A particular characteristic of our experimental set up is that the production and transfer of ferromagnetic particles towards the superconductor surface can be controlled. Examples of vortex lattice decorations, related to different types of studies, are reported with different analyses of the structure, and the long-range translational and bond-orientational microscopic order of decorated patterns.