We aim at studying the interface between a ferromagnetic (FM) thin film and a topological insulator (TI). For accessing the spin-polarised state in a TI system via current injection, and for creating axion strings, a ferromagnetic top layer has to be deposited onto the TI. There have been controversial reports about the magnetic properties of the coupled system and XMCD studies are suggesting a magnetic dead layer in the system Co on Bi2Se3 due to interfacial mixing. Our goal is to study the interfaces of a number of FM-TI systems that have been precisely engineered by molecular beam epitaxy using CRISP. Together with complementary XRD and SQUID data, we hope to be able to understand and control the FM-TI interface.