Magnetoelectric materials, combining properties associated with magnetic and ferroelectric memory applications (e.g. in hard drives) are difficult to prepare but would represent a huge stepforward in memory devices. One family of materials with the potential to show such properties is derived from the corundum (Al2O3) structure but with various combinations of cations (including those with magnetic moments) instead of Al3+ cations. We've recently used neutron powder diffraction to show how the magnetic behaviour of corundum-derived Mn2MnWO6 can influence its dielectric behaviour and we propose to investigate a second corundum-derived oxide, Mn2FeRuO6. By using neutron powder diffraction, we'll be able to see if a similar interplay between magnetism - crystal structure - dielectric properties exists in this oxide of a different corundum-derived crystal structure.