Coupled Magnetoelectric materials via Cation exchange

Magnetoelectric materials – those that exhibit coupled ferromagnetic and ferroelectric behaviour – are predicted to have applications in a wide range of electronic devices.We have been using low-temperature cation-exchange reactions to substitute paramagnetic ions into hybrid-improper ferroelectric phases with the aim of inducing magnetoelectric coupling.Following this approach, we prepared MnSrNb2O7, FeSrNb2O7, CoSrNb2O7 and NiSrNb2O7.Magnetisation data indicate all 4 samples exhibit low-temperature phase transitions to ordered magnetic states which are accompanied by lattice parameter anomalies, suggestive of magnetoelectric coupling. We propose to collect high-resolution neutron powder diffraction data from these phases, as a function of temperature, through the magnetic and associated structural phase transitions to establish the nature of these features.