Multiferroic materials are a rare case where ferromagnetism and ferroelectricity coexist. Bismuth Ferrite (BiFeO3) is of special interest as both properties order at room temperature and exhibit magnetoelectric coupling. Therefore, its use in functional thin film that combine multiferroic and ferromagnetic layers is of particular interest. Previous Polarised Neutron reflectometry was performed on LaSrMnO3 / BiFeO3 bilayer thin films with in-situ applied electric fields. A subtle, reversible shift in the interface region thickness was measured upon an applied field. While the data obtained thus far provides a good hint regarding the magnetic structure and coupling at the interface, so far we have only one scan with the required electric field. We plan to perform a series of scans to systematically probe the magnetoelectric coupling and interfacial physics of this system.