A recent exciting development in magnetic materials was the discovery of a new iron oxide, Fe4O5, using high temperature and high pressure. A very recent structural study has reveal an incommensurate charge order at 150 K below which dimeron and trimeron like groups of Fe ions are formed. Using high pressure and temperature methods, we have synthesised a new analogue, MnFe3O5. Magnetic susceptibility data reveal a broad Curie transition at TC = 150 K and a further magnetic and structural transition at 350 K. We request 2 days on WISH in order to collect high resolution powder neutron diffraction patterns from a 50 mg sample of MnFe3O5 over a wide temperature range (10-400 K). These data will be used to determine the magnetic structure and any accompanying structural changes.