The similar crystallographic structure allows to grow superconducting cuprates and ferromagnetic manganites as thin films epitaxially on top of each other. The generated interfaces can show an atomically flat structure. This high interface quality leads to a magnetic and an electronic coupling of both ordering phenomena, namely superconductinvity and ferromagnetism. The magnetic coupling leads to a hysteretic behaviour of the critical current density in these structures. The size of the effect is plotted vs. temperature for different heterostructures in the figure.