We have observed that the addition of C60 molecules on the surface of rare earth (RE) metal thin films alters magnetic transitions into collinear and non-collinear states. The molecules themselves may become weakly spin polarised. Here, we aim to explore the as yet unexplained origin of this effect and its possible applications. Critically for our systems, PNR is a unique technique in that it allows us to study the magnetic profile of samples composed of elements with very different atomic weights and properties, such as carbon and gadolinium, and without damaging the highly sensitive interfaces. Comparing measurements at the second order transition into the ferromagnetic state between Y/Gd and Y/Gd/C60 samples we will be able to determine the local magnetic moments and the spatial profile of the magnetic interaction.