The spin Seebeck effect is a newly discovered phenomenon that if harnessed, could result in a significant improvement of the efficiency of thermoelectric energy generators. Spin polarised neutron reflectivity will provide us with complementary measurements that enable determination of the spin polarisation of the film as well as surface sensitive magnetic ordering and disorder at the interface. This is especially important as the influence of the interface (i.e. the magnetic proximity effect) is still not well understood. We plan here to obtain complementary measurements to resonant magnetic x-ray reflectivity (XMaS, ESRF) to determine the change in proximity effect from a metallic to insulating state in Fe3O4:Pt bilayers.