Using high-temperature high-pressure synthetic methods we have recently prepared the new quadruple perovskite CaFe3Ti4O12. Curie-Weiss magnetic susceptibility and Mossbauer data also confirm the presence of Fe2+ S = 2 spins. Magnetic susceptibility data show a maximum at 2.8 K suggesting AFM (antiferromagnetic) ordering of the Fe2+ spins. However the AFM feature in the magnetic susceptibility data is suppressed when measured under high applied magnetic fields, and the same effect is observed in heat capacity data. DFT calculations for the AFM and FM spin arrangements for the Fe2+ spin sublattice in CaFe3Ti4O12 reveal that the two states are very close in energy. We therefore would like to perform neutron diffraction experiments under different temperatures and applied magnet fields to characterise the competition between AFM and FM ground states. We request 3 days on WISH.