Cation-exchanged layered perovskite oxides

Ferroelectric materials (those which exhibit spontaneous and switchable electrical polarizations) have a wide range of applications. However preparing new ferroelectric materials is challenging because they are required to have a non-centrosymmetric crystal structures, which are generally disfavoured on thermodynamic grounds.We have been working of a strategy of introducing ferroelectric behaviour into phases via low-temperature cation exchange reactions. Specifically, we are exploring the cation exchange chemistry of polar Dion-Jacobson and Ruddlesden-Popper oxide phases to see if we can induce ferroelectric behaviour by modifying the collective distortions of their frameworks. We propose to collect high resolution neutron powder diffraction data from these exchanged phases, so we can determine their complex structural distortions, and thus determine the effect of cation exchange.